摘要:

ACTION OF LIGHT OY ANTL ALCOHOL. 1349 LLYXXV.-Aciiion of Li,qht on AmyZ Alcolzol. By ARTHUR RICHARDSON, Ph.D., and EMILY C. FORTET, B.Sc., University C ol lege, B ris tol. IT has already been shown that ether (Trans., 1891, 59, Sl), phenol (J. SOC. Ckem. Ind., 1893, 12, 415), and oxalic acid (Trans., 1894,65, 450) yield hydrogen peroxide on exposure to sunlight in presence of oxygen. A number of other organic substances have been tested for hydrogen peroxide after exposure to light, and among those which have been found to yield a very noticeable quantity of this substance may be mentioned amyl alcohol, palmitic, and stearic acids suspended in water, and acid solutions of some of the alkaloids. A more detailed study of the action of light on amyl alcohol was undertaken in order to determine the nature of the change which occum, care being ta.ken to ensure the greatest purity in the material used; the object of the present paper is to give the results of that investigstion.The sample of amgl alcohol used in the following 4 x 21350 RICHARDSON ASD FORTET : experiments was obtained from Kahllsaum, and after being dried for 48 hours over lime, was treated with minute qunnt,it,ies of metallic sodium and distilled twice. Formation of Bydrogen Perozide.-Two experiments out of a large number which were made will suffice to illust8rczte tlie ease with which hydrogen peroxide is formed during exposure to sunlight and oxygen. I n the first case, a considerable quantity of water was pr.esent,whereas, i n the second, the alcohol was only in contact with moist oxygeri.I. About 10 C.C. of amyl alcohol were exposed together with 50 C.C. of water in presence of oxygen. After a few days a portion was tested, and the presence of a large quantity of hydrogen peroxide in the aqueous solntion was shown by a deep orange coloration with titanic acid, Another portion of the water also gave an intense blue colour with pure ether and potassium dichromate. The layer of alcohol itself gaye only a faint coloration with titanic acid, hydrogen peroxide being apparently more soluble in water than in the alcohol. 2. In tlie next experiment, arnyl alcohol was exposed in presence of moist oxygen, liquid water being absent. After only two days' ex- posure, the alcohol contained a large quantity of hydrogen peroxide as shown by the titanic acid test.No hydrogen peroxide could be detected in the alcohol which had been kept in the dark either in presence of water and ox-j-gen, or of moist oxygen alone. Having ascertained the fact that hydrogen peroxide is formed when amyl alcohol is exposed to sunlight in presence of moist oxygen, with or without addition of liquid water, i t seemed desirable to determine whether a similar result would be obtained with the dry alcohol. To this end the following experiments, among others, mere carried on t. InJluence of dloistzu-e.-l. A small sealed tube containing any1 alcohol, which had been dried over nietallic sodium, mas broken inside a larger one through which oxygen dried over phosphorus pentoxide had been previonsly passed, and the tube was exposed to sunlight for 17 days.It was then opened, and the liquid, when tested, gave strong peroxide reactions, both with titanic acid and with potassium dichromate and ether. 2. To ascertain the influence of further desiccation, a quantity of pure amyl alcohol dried as before, and contained in a small sealed tube, was placed in a bent tube, containing phosphorus pentoxide at one end, and filled with dry oxygen. The inner tube was broken, care being taken not t o allow the liquid to wet the pentoxide, and the tube was kept in the dark for seven weeks. The amyl alcohol so dried was then exposed to sunlight for two weeks, and when tested was found to contain abundance of hydrogen peroxide. It seems, I t boiled constantly a t 132.6' (corr.).ACTTON OF LIGHT ON BIIE’L ALCOHOL.1351 then, that the absence of moisture, in so far as it was ensured by the precautions adopted, does not prevent the formation of hydrogen peroxide in nmyl alcohol when exposed in presence of oxygen. Other Products.-The next point was to ascertain whether any other products were formed. A quantity of amyl alcohol which had becn exposed t o sunlight for some months was now strongly acid, and smelt distinctly of valerianic acid. The presence of this substance mas further proved by neutralising with sodium carbonate, separat- ing from the excess of alcohol, decomposing the sodium salt by means of dilute hydrochloric acid, and extracting with ether. On distilling off the ether, an acid liquid remained, possessing the characteristic smell of valerianic acid.The formation of this acid seemed to indi- cate that the change occurring was one of a comparatively simple nature, not involving the breaking down of the molecule. To further examine this point, several samples were carefully tested for carbon dioxide after long exposure to light in sealed tubes. The gas above the liquid in sucli cases was aspirated through solutions of barium hydroxide, which showed no signs of turbidity, proving that carbon dioxide was entirely absent. It seems, then, that the products formed by the oxidation of amyl alcohol under the influence of sunlight and oxygen only differ from those yielded when other oxidising agents are used, i n that hydrogen peroxide tends t o be formed instead of water. The change ma,?, therefore, be repesented by the following equation : 2C5Hll*OH + 302 = 2G4Hg.COOH + 2H202.E’ect c?f Temperatwe.-It now seemed of interest to determine whether an increase of temperature would bring about the formation of hydrogen peroxide in the dark. A tube containing amyl alcohol and oxygen was, therefore, placed in the steam chamber at 100’ and heated for nine days. On opening it, the contents gave no acid reaction with litmus, and not a trace of hydrogen peroxide could be detected, showing the complete stability of amyl alcohol in the dark at temperatures beiow 100’. I t may be mentioned that i n the case of ether, oxidation had been found to take place under the above conditions (Trans., 1891, 59, 51). The tendency of nmyl alcohol to yield hydrogen peroxide on exposure to light led us to inquire into the behaviour of some of the lower alcohols. Very carefully piirified methyl, ethyl, and propyl alcohols were exposed to light in presence of excess of water and of oxygen, and also in tubes containing moist oxygen only. After periods varying from a few clays t o six months, methyl alcohol, when tested, gave no sign of hydrogen peroxide, and remained neutral to litmus. Xthyl a,lcohol, which seemed t o show the presence of a trace of the peroxide at the end of a few weeks, was, however, entirely free from i t after1352 RICHARDSON ASD FORTET : prolonged exposure, and was neutral to litmus. n-Propyl, isopropyl, and isobutyl alcohols were also tested, and negative results were obtained in every case. It is, therefore, surprising that the next higher alcohol, amyl alcohol, should show so marked a change in its behnviour under the same conditions. With regard to the higher alcohols, octyl alcohol alone has been tested, and the sample used was found to give a, small but distinct indication of hydrogen peroxide aftel. an exposure of two weeks.

ISSN:0368-1645    

DOI:10.1039/CT8966901349

出版商:RSC    

年代:1896

数据来源: RSC

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1352 RICHARDSON ASD FORTET : LXXXV1.-Note on the Action of Light o n Ether. By ARTHUR RICHARDSON, Ph.D, and EMTLY c. FORTET, B.Sc., University College, Bristol. THE researches already published by one of us (Trans., 1891, 59, 51) on the formation of hydrogen peroxide in pure ether showed that when the ether was dried by long contact with metallic sodium, i t still yielded considerable quantities of hydrogen peroxide when exposed to sunlight, in presence of dry oxygen. Experiments have since been undertaken with still further precautions to remove the last traces of moisture, and the resirlts give a full confirmation of the previous work. The ether used in this investigation mas prepared from pure alcohol and pure sulphuric acid, and, after repeated washing with water t o remove traces of alcohol, was shaken with potassium dichromat,e according to the method of purification described by Dunstnn and Dgmond (Trans., 1890, 57, 574).After being dried over phosphorus pentoxide, it was distilled into tubes without contact with the air by means of the following arrangement. The flask A, fitted tyit'h an air-tight stopper, a, is connected with tile flask C by means of the U-tube B. C is connected with a. series of tubes drawn out, as shown in the figure, and terminating in the bulb D. I n the first place the ether was distilled into A and allowed t o stand over phosphorus pentoxide for two clays, the stopper having been inserted and made air-tight by means of mercury in the cup a', and the connection between A and C being cut off by means of a column of mercury in the U-tube.The exit tube a t d being open, the ether was then distilled over into C, which also contained phos- phorus pentoxide, and was kept cool by a freezing mixture, the mercui-y in the U-tube being forced into the bulb b by the pressure of the rapour in A. It was next distilled from C (which was again uhnt off from A by the falling back of the mercury into the U-tube) iilto tthe flask D, which also contained phosphorus pentoxide. TheTHE ACTION OF LIGHT ON ETHER. 1353 whole system was thus filled with ether, and its vapour issued at d, and at this stage the latter exit was sealed. Then, by cooling C and slightly warming D, the whole of the ether was caused to collect in C, and the reverse process returned it again to D. After the end of a week, during which time the apparatus had been kept in the dark, the whole of the liquid mas transferred to C, and the last tube, E, was sealed off from D.Ether was now distilled into E by immers- ing the tubes in a freezing mixture, and, when nearly full, it was sealed off at the capillary neck, The rest of the tubes were filled in a similar way, and were sealed off ready for use. It is evident that by this process the desiccation of the ether can be effectually carried out, and samples obtained in hermetically sealed tubes without risk of condensation of aqueous vapour from exposure to air. One of the tubes was placed in a larger one filled with dry oxygen and containing phosphorus pentoside. The tube was left standing in the dark for nipe weeks, and was then sealed off at a, constriction shomii in the figure at A.The inner tube was then broken, and the whole exposed to sun- After three days, the tube was opened and the ether tested light.1354 THE ACTION OF LIGHT ON ETHER. with titanic acid. A deep orange coloration was produced, proving conclusively that hjdrogen peroxide was present in considerable quantity. It is thus seen that the utmost precautioiis to remove all +,races of moisture do not prevent the formation of hydrogen peroxide when etcher is exposed to sunlight in presence of oxygen, nor do they appear to diminish the quantity produced. It may be of interest to note here that two experiments mentioned in a previous paper by one of us (Trans., 1891, 59, 51) to test the influence of temperature on the formation of hydrogen peroxide in ether kept in the dark have been repeated and the results confirmed.h flask containing ether and oxygen was heated for some days in the steam chamber at 100'. The contents were then found to be acid t o litmus, and to contain hydrogen peroxide. A second flask, contain- ing so s mall a, quantity of ether that all was vaporised on placing it in the steam chamber, was treated similarly, and on opening it the contents were found to he acid, but no trace of hydrogen peroxide could be detected, The latter result might have been anticipated from the fact that hydrogen peroxide is unstable in the state of vapour. It should thus be borne in mind, in studying the formation of hydrogen peroxide in organic compounds, that its stability under the conditions of experiment has an important bearing on the matter when deciding whether it is formed in any particular liquid or not.Taking advantage of the intensity of the sunlight this year, an experiment was made with the object of determining how far solar heat alone would bring about the decomposition of ether. To this end, a tube containing ether and oxygen mas exposed to the heating effect of the sun's rays, being, however, carefully protected from light. After an exposure of six weeks, the ether was found to contain minute traces of hydrogen peroxide, but in no way approaching the quantity formed when it has been exposed to light for a very much shorter period. Dunstan and Dymond have laid considerable stress on the influence of tempemture in addition to that of sunlight in bringing about the formation of hydrogen peroxide in ether (Trans., 1890, 57, 988).It has, however, been shown (Trans., 1891, 59, 51) that ether exposed to light at 0' yields hydrogen peroxide freely, thus p,roving that decomposition can be effect'ed under the influence of sunlight at comparatively low temperatures. No special study having been previously made of the other pro- ducts of the decomposition of ether when exposed to light in presence of oxygen, it seemed now of interest to determine this point. A quantity of ether, which had been exposed f o r five weeks in presence of water and oxygen, and which now contained large quantities of hydrogen peroxide, was tested and found to be strongly acid, as was also the aqueous solution.Sodium carbonate was then added, andCOFSTITUTION O F LAPACHOL AND ITS DERIVATIVES. 1355 the excess of ether, together with any other volatile products which might have been formed, distilled off on the water bath. The distil- late smelt strongly of aldehyde, and this was proved to be present by its reducing action on ammoniacal silver nitrate, and also by its restoring the colour to a solution of rosaniline hydrochloride decolorised by sulphurous acid. The aqueous solution mas then evaporated down, and, after the addition of dilute sulphuric acid, i t was distilled. The distillate was neutralised, and a portion tested for acetic acid with ferric chloride, and the presence of the acid was proved by the red coloration produced. This was confirmed by heat- i n g mother portion of the distillate with alcohol and sulphuric acid, when a strong smell of ethylic acetate was observed. Experiments also showed that no carbon dioxide was formed during the decom- position of ether in sunlight, and it seems probable that the change consists in the oxidation of the ether first to aldehyde and then to acetic acid, together with the formation of hydrogen peroxide. The final result may, therefore, be represented by the equation 2(C2H5),0 + 502 4CzHdO2 + 2H2Op It seems, then, t'hat in this case, as in the case of oxalic acid (Trans., 1894, 65, 450), amyl alcohol, and certain other organic siib- stances, hydrogen peroxide is formed in the place of water, which would be a normal oxidation product.

ISSN:0368-1645    

DOI:10.1039/CT8966901352

出版商:RSC    

年代:1896

数据来源: RSC

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COXSTITUTION OF LXPACHOL AND ITS DERIVATIVES. 1355 LXXXVI1.-Tize Constitution of Lapaclzol and its Deri- vcctiws. Part IIJ. The Xtmcture of the Amylene C'hCLi?Z. By SAMUEL C. HOOKER. 0 regarding the constitution of lapachol. It is true that Patern6 assigned to the -C,Hg group the structure -CB:CHCH<CH3, CH3 and that I have adopted this in my former papers, but I have been carefnl to point out that this formula was employed provisionally only (Trans., 1892, 612 ; 1893, 430). In assigning the above constitution to the -C5Hg group, Patern6 was mainly influenced by t h e two following reasons.1356 HOOKER : THE CONSTITUTION OF LAPACHOL I. He had identified isobutylene among the reduction products resulting from the distillation of lapachol over zinc dust. 11. He believed that he had obtained P-iso-amylnaphthalene by submitting Iapachol to the action of hydriodic acid and phosphorus.The substance obtained mas not, however, P-iso-amylnnpht halene, as was subsequently proved by the synthesis of this compound by Roux (BuZZetin, 1884, [2], 41, 380). P-Iso-amylnaphthalene diff ers essentially from Paternh’s hydrocarbon. Thus, since the publication of Roux’s paper, the only two experi- ments bearing on the structure of the amylene chain lead to contrary conclusions. On the one hand, the formation of isobutylene points to the probability that the -C5Hg group contains isopropyl ; and, on tlio other, the dissimilarity between Paternb’s hydrocarbon, CIOHII.C5H1,, and the /3-iso-amylnaphthalene prepared by ROUX, renders the pre- sence of isopropyl improbable.The results of the experiments now to be communicated to the Society clearly prove that the amylene chain of lapachol must be written -CHz*CH:C<c,2, and not -CH:CH*CH<Eg:, as has been previously assumed. It has been shown by Hooker and Carnell (Trans., 1891, 65, 84), that isovaleraldehyde and P-hydroxy-2-naphthaquinone, when heated in alcoholic solution, interact according to the following equation, I. 2CloHs03 + CaHg*CHO = C,Hg*CH(C,oH,03), + HZO; but if the same substances, dissolved in acetic acid, are heated in the presence of a sufficiently large quantity of hydrochloric acid, the following entirely different reaction occurs (compare Proc., 1893, 9, 259). C,Hg*CHO = CloH, I n the first case, the isovaleraldehyde unites with 2 mols.of the hjclroxynaphthaquinone, an action which appears to be a general one, and which was first studied by Zincke and Thelen with benzaldehydo ; in the second, the same quantity of the aldehyde unites with 1 mol. of the hydroxynaphthaquinone only,* and the resulting compound, C,,H,403, is isomeric with lapachol. That the action has occurred as above indicated, is cleai4y demon- strated by the following facts. f Further details of this reaction, so f a r as other aldehydes are concerned, will be communicated later.AND ITS DERIVATIVES. 1357 1. The cornpound exbibits all the properties of a liyclroxyquiiione. Having well developed acid properties, it dissolves readily iu alkalis, and forms intensely coloured, crystalline salts. 2. It yields an acetyl derivative, which is no longer capable of forming salts.3. When oxidised with nitric acid, i t yields phthalic acid. 4. It combines readily with bromine, forming an iinstable additive compound, in which the bromine, as is apparent from the reactions of the compound, is unquestionably situated in the side chain. These properties demonstrate 1. That the quiuone group has taken no part in the reaction. 2. That the hydroxyl group also remains undisturbed. 3. That the side chain must be sitaated in the benzene ring con- taining the quinone and hydroxyl groups, and consequently that it nccupies the /I-position, which is the only one available. 4. That there is a double bond present in the side chain. If, therefore, the origin of isolapachol from /3-hjdroxy-z-naphtha- quinone were alone considered, i t would be necessary to assign t o it the first of the following formulze, 0 013 but as isolapachol differs from the derivatives of &hydroxy-x-naphtba- quinone, in being of it brilliant brick-red colour instead of yellow, we must accept the second formula as the more probable one.(Corn- pare pp. 1363, 1364.) The first of the above formula is that which, up to the present time, has been used as probably representing the constitution of lapachol, and thus the question arises, does the isomerism existing between lapachol and isolapachol merely depend on a difference in the qninone group? This can be readily answered in the negative, for i f t'hese compounds were related as shown in the formulae (1) and (a), it is evident that on reduction they both must yield the same hydro- Inpachol, but as this is not the OH case, the amylene chain in lapachol cannot be1358 HOOKER : THE CONSTITUTION OF LAPACHOL identical with that in isolapachol ; hence the above formula (1) can no longer be iiccepted as representing the structure of lapachol.” I shall show in the €allowing pages that lapachol aiid isolapachol can be converted without loss of carbon atoms into the same com- pounds.The changes involved are simple, and could hardly give rise to any alteration in the skeleton structure of the side chain, which must, therefore, in both cases be written -C*C.C<gI, the car- bon atom to the ext’reme left being attached to the naphthalene nucleus. This follows as a necessary consequence from the synthesis of isolapachol from isovaleraldehyde. Now, from a skeleton of this structure, it is only possible to derive three amylene chains, namely, (1) (2) ( 8 ) and of these the first, being that present in isolapachol, cannot represent the structure of the chain in lapachol itself, whilst the third will not explain the reactions of lapachol, more particularly those connected with the passage of its derivatives into those of iso- lapachol. - There remains consequently the second formula only, and this alone enables all the numerous reactions already studied to be satisfactorily interpreted. The reduction of lapachol, if carried sufficiently far, might, there- fore, be expected t o lead to P-iso-amylnaphthalene, the hydrocarbon which Patern6 believed to be formed by the action of hydriodic acid and phosphorus.As already stated, however, /j-iso-amylnaphtha- leiie has been synthesised by ROUX, and it differs essentially from Paternb’s hydrocarbon. Paternh’s conclusions regarding the composition of his reduction product cannot., therefore, be accepted, for if the compound obtained were really CloH7*C5H11, i.e., an amylnaphthalene, it is evident that the amylene chain in lapachol could not have for its structure the CH3 formula, -CH,*CH:C <CH9’ which the results of my experiments necessitate. I have therefore repeated in more detail Paternb’s work, and have found that the reduction product described by him is not a hjdrocarbon, but a mixture of two isomeric compounds of the formula, C15H160. In order to understand the formation of these compounds, it is only necessary to remember that, by the action of mineral acids, The possibility of stereoisomerism has not been orerlookecl ; the assumption of its existence is however unnecessary. The relation of lslpacliol and isolapachol to each other, as will be preseiitly seen, is made perfectly clear by their reactions.AYD ITS DERIVATIVES. 1359 lapnchol is readily converted into either a- or P-lapachone, or a mix- ture of these substances ; and as the lapachones coiitain a closed side chain, in which the hydroxylic oxygen forms the connecting link between the amylene group and the naphthalene nucleus, i t is evident that some difficulty might be anticipated in the removal of the whole of the oxygen ; hence it is not surprising that the reduction products obtained should have the formula, ClOH3[,< I C&O 0 .No analysis is given by Paternb of his supposed hydrocarbon, bnt. its composition was deduced by him from the following analyses of a picrate prepared from it. Calculated for Paternb found. C l ~ € I j * C ~ H ~ ~ + C,H2(NO2)3*OH. C.. .... 57.41, 57.29, 57.27 59.01 H ..... 4.61, 4.76, 5.15 4-91 N ..... Not determined. 9-83 Patern6 explained the deviation of his analytical results from those required by the formula C15H18,C6Ha(NOz)3*OH, by the supposition that the picrate analysed contained small quantities of free picric acid. The analytical figures given below are the averages of all those obtained ; that is, they include the results of Paternb’s analyses, as well as those of my own ; and the comparison shows that they agree with the requirements of the theory suggested above.This explanation is however, no longer tenable. Calculated for Mean of the CljHlG0,C,jH2( N02),*OH. analytical results.* C ............. 57.14 57-14 H ............. 4.30 4.57 N ............. 9.52 9.61 I have further confirmed the formula C15H160, by the analysis of the reduction product itself (compare p. 1367), and have found t,hat of the two substances of which it is a mixture, the one- that predominating-can be obtained by the reduction of P-lapachone, whilst the other, which appears t o be present in a small quantity only, can be readily prepared by the reduction of a-lapachone. There is, therefore, no doubt possible regarding the composition of Paternb’s reduction prodnct, and the discovery that it contains oxygen has remored the difficulties which, as a hydrocarbon, its existence sug- gested.The conversion of the derivatives of lapachol into those of iso- lapachol, to which reference has been already made, can be best shown graphically as follows. * For details compare p. 1366.Tnutomcric formuloe (3) probably corresponds to the st,a,blc form. cj K P B 1- f- Q .. c3 pi n Q 3 Q !a 0 0 w d Changes spontaneously 2. in alcoholic solution 5 *-p a A 83 QQ A w w Effi bQAND ITS DERIVhTlVES. 1361 The revision of the formula of lapachol renders necessary some modification in the formula: of the remaining substances of this group ; these changes may now be briefly discussed. The conversion of lapachol into the isomeric lapachones has been shown to depend on the absorption of a molecule of water, which is again subsequently eliminated, but in a different direction (Trans., 1892,61,613) ; and there is every reason to believe that in the forma- tion of the intermediate additive compound the general rule has been followed, and the hydroxyl or negative group has attached itself to the carbon atom poorest in hydrogen. Consequently the following formuls must be ascribed to hydroxyhydrolapachol and lapachone respectively.C H, C ,,Hk CH2* C € € , d O H ‘CH3 H y droxjhy drolapachol. C,,H, {::-I CH2*CH,*C<;Z Lapachone. {:H Similarly, chlorhydrolapachol becomes 0 and bromo-P-lnpachon e 0--1 Thus, the side ring of the lapachones consists of six members, instead of five, as has been heretofore assumed. That a similarity exists between the lapacbones, on the one hand, and the anhydrides of the syiithetical compounds oE the general formula X 0 CH 0 I on the other, has been established by Hooker and Carnell (Trans., 1894, 65, 76).In the case of the latter compounds, the anhydride formation can only give rise to a ring consistiug of six members, hence the lapachones are more closely related to this group than was a t first suppmed.1362 HOOKER : THE COBSTITUTIOS OF LAPACHOL The only remaining compound of the Iapachol group t o which it seems necessary to make special refererce in the introductory portion of this paper is Paternh’s so-called isolupuchoute. In a former comniu- nication to the Society (Trans., 1892,61, 624), i t was shown that this compound contains 2 atoms of hydrogen less than lapachone : it has, in cousequence, the formula Cl5Hl1OB, being isomeric with dehydro- lapachone (see next paper) and the isopropylfuran-nnphthaquinones (pp.1370, 1376). The structural formnla provisionally suggested at that time, revised in accordance with the requirements of the new formula for lapachol, is, however, no longer tenable. I shall hope to discuss in the near future the results which have led to this conclusion. In the meantime the compound may be conveniently referred t o as pseudo-dehydrolapachone. EXPERIMENTAL PART. Xynthesis of Iso-/3-lapachol (compare Proc., 1893, 9, 259) .-This compound, to which reference has already been made on p. 1356, was prepared as follows :-lo grams of hydroxynaphthaquinone were heated on a st’eam bath with 175 C.C.of acetic acid. As soon as the substance had completely dissolved, 35 C.C. of isovaleraldehyde, immediately followed by 50 C.C. of concent rated hydrochloric acid 9 sp. gr. 1-20, were added; the flask was a t once returned to the steam bath, and the heating continued for exactly 20 minutes. The solution was then poured into a relatively large volume of water. The dark oil which rose to the surface commenced to crystallise almost immediately. After standing over night, the crystalline crust was lifted off, allowed to drain, and finally repeatedly pressed between porous paper, so as to remove the oil as thoroughly as possible. The substance was then crystallised from a small quantity of alcohol.* Two preparations were made, the one from Kahlbaum’s “valer- aldehyde,” the other from isovaleraldehyde synthesised from iso- butylic iodide.The purified products were found to be identical, equally satisfactory results being apparently obtained with Kahl- baum’s valeraldehyde, although optically active, as with the aldehyde synthetically prepared. The yield is very fair, from 7 t o 9 grams of the purified substance being obtained from 10 grams of hydroxy- naphthaquinone. * The alcoholic mother liquor, after concentration to a small bulk, so as to first yield a second crop of crystals, wan poured into about 400 C.C. of an aqueous 1 per cent. solut,ion of sodium hydroxide. The iso-8-lapachol which remained in the mother liquor was thus extracted by the alkaline solution, from which, after filtra- tion from the resin, it mas precipitated by hydrochloric acid as an orange oily substance, which gi*adunlly became crystalline.AKD ITS DERIVATIVES.1363 Iso-p-lapachol was prepared for analysis by recry stallisation from It separated i n brilliant, brick-red needles, which melted at The alcohol. 120°, showing signs of fusion at a slightly lower temperature. following figures were obtained on analysis. T. 0.2035 gave 0.5528 CO, and 0.1071 H20. C = 74.08; H = 5-84, 11. 0.1991 ,, 0.5400 ,, ,, 0.1057 H20. C = 73.97; H = 5.89. ClsHlrOa requires C = 74-38 ; H = 5-78 per cent. Dilute aqueoiis solutions of sodium and potassium hydroxide dis- solve iso-P-lapachol readily, becoming intensely purple. From these solutions the corresponding salts can be easily obtained in a crystal- line condition by the addition of a concentrated solution of the respective hydroxide ; when dry, the salts are dark violet, almost black.In alcohol, more especially when in dilute solution, i t slowly undergoes change, the odour of acetaldehyde becomes noticeable, and a yellow, granular, although crystalline, substance, sparingly soluble in alcohol, separates. This dissolves to some extent in 1 per cent. sodium hydroxide, but is apparently mostly converted into a salt by the alkali mi thout passing into solution. Iso-P-lapachol is dissolved by concent,rated sulphuric acid to a solution, which, after passing through various shades, soon becomes crimson, the odour of sul- phurous acid being distinctly perceptible. The precipitate obtained on the addition of water became resinous on drying, and consisted of more than one substance.Several attempts were made to form an additive compoiini: with hydrogen chloride and hydrogen bromide respectively, as it wa0 thought possible that if such a compound were obtained i t might serve as a stepping-stone to the preparation of lapachol itself: these experiments have proved entirely unsuccessful. The constitution of iso-p-lapachol has been already discussed in the theoretical port~ion of this paper. Reference may, however, be made somewhat more in detail to the fact that I have assigned to i t the structure of a P-naphthaquinone derivative. This has been done became it is extremely probable that the difference in colonr between a- and p-naphthaquinone derivatives of the types occurring in the lapachol group is a sharp and distinct one.Iso-p-lapachol is very soluble in the ordinary organic solvents. In previous papers I have regarded the structure OH VOL. LXIX. 4 P1364 HOOEER : THE CONSTITUTION OF LAPACHOL as an nnst'able one, but the existence of iso-/3-la,pachul, as well as of similar compounds which have since been prepared in my laboratory, renders it probable that although frequently unstable this structure is not necessarily so. In the case of the internal anhydrides of the general formulze Red. Yellow. the relation of colour to structure can be readily established. Thus we have the red anhydrides which, without exception, form azines, and the yellow ones which do not ; and whilst it is not possible with any degree of certainty t o apply the azine test to the hydroxy- naphthaquinone derivatives themselves, owing to the mobility of the hydroxylic hydrogen, it may nevertheless be presumed, with a fair amount of probability, that a similar relation to colour in their case also holds good.Hence the red and yellow hydroxynaphthaquinones must, for the present at least, be regarded as ortho- and para-qninone derivatives respectively. Acetyl Derivative.-An acetyl derivative was readily obtained by boiling for two or three minutes 2 grams of iso-P-lapachol with 4 grams of anhydrous sodium acetate and 13 C.C. of acetic anhydride ; the solution was then poured into a large volume of water ; the oil which separated soon became crystalline. The acetate was purified by crystallisation from alcohol, in which it dissolves very readily, and from which it separates as yellow needles.The portion f o r analysis was again recrystallised, and then melted sharply at '74'. The analytical results were as follows. 02128 gave 0.5568 COz and 0.1071 H,O. Cl,H13(COCH3)0, requires C = 71.83 ; H = 5.63 per cent. The acetate, being yellow, is most likely an a-naphthaquinone derivative. Thus i t is probably derived from isolapachol, the /3-hydroxy-a-naphthaquinone derivative isomeric with iso-/3-lapachol. Concentrated sulphuric acid gives with the acetate a violet colora- tion, which rapidly changes into crimson. The acetyl group is readily removed by caustic alkalis ; the compound was boiled for a short time with a 1 per cent. solution of sodium hjdroxide until it had completely dissolved ; hydrochloric acid precipitated iso-6'- lapachol from the alkaline solution, and this, when once crystallised from alcohol, fused a t about 119.5".Por the analyses of iso-/3-lapachol, and also those of the acetate, I C = 71.36; H = 5.59.AND ITS DERIVATIVES. 1365 am much indebted to MI*. C. C. Burger, who also rendered valuable assistance in the preparation of these compounds. Reduction of LapchoZ.--'rhis was conducted essentially as de- scribed by Paternb (Garzetta, 1882, 12, 329). One payt of lapachol, one part of amorphous phosphorus, and four parts by weight of hydriodic acid, sp. gr. 1.7, were heated together until the action which is at first quite brisk, appeared to be entirely ended. The lower or oily layer was separated, washed slightly with water, and then distilled in a current of steam.The oil which collected in the receiver passed ovei* with very great difficulty, and the distillation mas continued for some da,ys. As a further means of purification, the oil wzs converted into the picrate described by Patern6. This was c~yst~allised from alcohol and then decomposed by a dilute solution of ammonia, the liberated oil being extracted by agitation with ether. The ethereal solution was repeatedly washed with water, dried over calcium chloride and distilled ; after the ether bad been driven off, the t,emperature rose rapidly and no further distillate was obtained until the thermometer registered over 300". The first por- tions of the oil vr-ere discarded: that collected for analysis passed over at about 3 1 0 O .The following figures mere obtained. I. 0.2256 gave 0.7075 COz and 0.1542 H,O. 11. 0.24'38 ,, 0.7596 ,, ,, 0.1671 H,O. Found. Calculated for 7-7 7--A- C ...... 85.52 84.97 84.90 90.90 7 I. 11. C15H160. ClOH7*C5Hll. H . . .... 7-59 7.61 7-54 9.09 It is apparent from these analyses that the oil is not an aniyl- naphthalene. The analytical results point rather to the formula CI5Hl6O, and this was further confirmed by the experiments given below. The action of hydriodic acid in giving rise to a reduction product, C15H160, is a two-fold one. The lapachol first merely under- goes the change which is brought about by all the stronger mineral acids, and which invariably results in the formation of a- or B-lapa- &one, or of a mixture of these substances. The quinone group is then completely reduced, and the product, Cl5HI6O, is formed.Theoretically, therefore, the formation of two isomeric substances is possible, the one derived from a-lapachone the other from p-lapa- chone ; and indeed it was subsequently foiind that the oil nnttlysed was a mixture of these two isomerides. They will in future be referred to as a- and 8-lapachan respectively. The reduction product as prepared above was amber coloured 4 ~ 21366 HOOKER : THE CONSTITUTION OF LAPACEOL when freshly obtained, but, subsequently, it darkened considerably, even though protected from the light. It does n9t appear to distil entirely without decomposition at the ordinary atmospheric pressure, and the slight colour of the freshly prepared substance was probably due to this cause.About nine months after preparation, a few perfectly colourless prismatic crystals had formed, whilst by far the larger quantity of oil still remained in a liquid condition. Efforts were then made to obtain enough of the substance in n crystalline condition f o r analysis, and in view of the theoretical explanation of the reduction process suggested above, a- and p- lapachone were in turn submitted to the action of hydriodic acid and phosphorus. It was thus found that the reduction of a-lapachone gave rise to a substance which crystallised readily, and which was identical with that deposited in crystals from the oil. p-lapachone, on the other hand, gave an oil which could not be obtained in a crystalline condition, and which was recognised by its picrate as being identical with the permanently fluid constituent of the oil obtained by the reduction of lapachol.A portion of the picrate obtained from the lapachol reduction product was several times recrystallised from alcohol and then an aly sed. 0.2564 gave 0,5367 C0,and 01036 H,O. C = 57.08 ; H = 4.48. 0.1847 ,, 0.3846 CO, ,, 0.0746 H20. C = 56.79 ; H = 4.48. 0.2013 ,, 0*4211 CO, ,, 0.0756 HzO. C = 57.05; H = 4.17. 0.2007 ,, lost ,, 0.0793 H,O. H = 4.39. 0.2484 20.8 C.C. moist nitrogen at 19.6' and 761 mm. N = 960. 0.1512 ,, 12.3 C.C. ,, ,, 162O r, 771 mm. N = 9.61. C15H,60,C6HZ(N02)3*OH requires C = 57.14 ; H = 4.30 ; N = 9.52 P.C. Subsequent to the discovery that there are in the lapachol reduc- tion product two distinct substances, a portion of the picrate analysed was carefully examined; i t was found to consist entirely of thc fi-lapachan derivative, the smaller quantity of the corresponding a-lapachan product having been entirely eliminated in the alcoholic mother liquors.In the substance which these deposited on el-apora- tion, the presence of a-lapachan picrate could be readily demonstrated. Reduction of a-Lapachone.-Twenty grams each of a-lapachonc and amorphous phosphorus were gently heated with 110 C.C. of hydriodic acid of sp. gr. 1.5. The action was moderated by occa- sional withdrawal from the source of heat, and when it appeared to be ended, the temperature was raised to, and maintained at, the boiling point f o r a few minutes. The resulting oil, after thorough washing with hot water, was dissolved in alcohol and freed from phosphorus by filtration.The a-lapachan present was then converted ,,AND ITS DERIVATIVES. 1367 by the addition of picric acid (15 grams) into its picrate which separated readily, and was purified by recrystallisation several times from alcohol. Rather more than 10 grams of the picrate was thus obtained in a satisfactory condition, although its colour remained persistently darker than that of the pure substance. From the alco- holic solution of the picrate, a-lapachan was obtained by the addition of sodium hydroxide dissolved in a little water, in quantity theoreti- cally sufficient to combine with the picric acid. I t was prepared for analysis by recrystallisation from alcohol, a small quantity of a much less soluble compound being thus removed. The substance first nnalysed was slightly coloured, treatment with animal charcoal having failed to produce a perfectly white product.C = 84.24; H = 7.35. I. 0.2375 gave 0.7336 C02 and 0.1573 H,O. 11. 0.1824 ,, 0.5657 (202 ,, 0.1202 H2O. C = 84-58 ; H = 7-32, 111. 0.1698 ,, 0.5252 CO, ,, O.113OH2O. C = 84.35 ; H = 7.39. C15H,,0 requires C = 84.90 ; H = 7-54 per cent. As the above fjgures were not entirely satisfactory, the preparation was further purified by distillation with steam, followed by recrystal- lisation from alcohol. It then melted sharply at 112.5 to 113*5O, was perfectly white, and gave analytical results as follows. 0.1822 gave 0.5655 CO, and 0.1255 H,O. a-Lapachan crystallises in long and remarkably brilliant needles readily soluble in hot alcohol. I n concentrated sulphuric acid, it dissolves to a yellow solution : the addition of water produces in this a milkiness which slowly gives way to a formation of microscopic crystals.With picric acid, it combines very readily, the acid chang- ing instantly to bright red on coming in contact with an alcoholic solution of a-lapachan. The picrate crystallises well from alcohol in red needles, being only moderately soluble in the cold: dilute s o h - tions are, however, apt to deposit some crystals of a-lapachan simultaneously with the picrate. The picrate melts sharply at 140°, and gave the following ana- lytical results. C = 84.64; H = 7.65. 0.2181 gave 0.4380 CO, and 0.0821 H20. C = 57.27 ; H = 4.18.C,5H,,0,C,H2(N02)3~OH requires C = 57-14 ; H = 4-30 per cent. Reduction of P-Lapachone.-This was conducted essentially as pre- viously described for the corresponding a-compound ; the resulting oil, still enclosing amorphous phosphorus, was distilled with steam. The P-lapachan, which collected as an oil in the receiver, was filtered off from the water, dissolved in alcohol, and converted into its picrate. After recrystallisation, the latter fused a t 143-144*, and was recognised as being identical wit'h the picrate previously1368 HOOKER : THE CONSTITUTION OF LAPACHOL obtained from lapachol, of which analyses are given on page 1366. I n spite of the melting point, being only 3-4" higher than that of the picrate of a-lapachan, and that i n appearance the two are essentially identical, the picrate of P-lapachan can be readily recognised by the intensely blue-green colour which it yields when slightly warmed with coucentrated sulphuric acid, a colour which p-Iapachan itself develops under the same circumstances, but which in the case of a-lapachan and its picrate is entirely wanting, the last two substances giving only a yellow solution.I n consequence of their mode of formation, the following formuh must be amscribed t o a- and B-lapachan respectively. 0-7 a-Lapachan. &Lapachan. In the foregoing experiments I am indebted for valizable assishance t o Mr. H. L. Wood, who undertook the somewhat tedious prepara- tion of the lapachol reduction product, and also made several of the analyses of its picrate. Action of Sdphzt~ic acid on Dihydroxyh yds.olapacho1.If dihydroxyhydrolapachol be dissolved in concentrated sulphuric acid, the solution, at first orange-red, almost instantly passes into a brown, and then more slowly into a dingy purple-red. Action takes place simultaneously in three directions, giving rise to the formation of hydroxy-/3-lapachone, isopropylfuran-a-naphthaquinone, and iso- propylf uran-/3-naphthaquinone. The changes involved are as follows. I. Hydroxy-P-lapachone is formed, Dih ydroxyhydrolapachol. Hydroxy-B-lapachone. 11. Dihydroxyhydrolapachol is converted into hydroxyisolapachol, Not isolat,ed.AND ITS DERIVATIVES. 1369 0 0 0 0 Hydroxyisolapachol. 111. Hydroxyisolapachol then gives off water, and is simultaneously converted into its internal a- and P-anhydrides, 0 - 0 Hjdroxy isolapachol.Isopropy If uran-a-naphthaquinone. 0-7 Isopropplf uran-8-nap~haquinnne. Whilst it is not possible to isolate hydroxyisolapachol under the above circumstances, because it so readily undergoes furkher change, its formation as an intermediate product can be demonstrated by employing sulphuric acid somewhat diluted, but even in this case small quantities only escape further action. That the change into the isopropylf uran-naphthaquinones takes place through the interrnediat!e stage as above shown is further proved by the reconversion of both the anhydrides into the same hydroxyisolapachol by boiling aqueous solutions of the alkalis. The hydroxyisolapachol thus isolated, when snbmitted to the action of concentrated sulphuric acid is again con- verted into a mixture of both anhydrides.The above interpretation of the dehydration of di hydroxyhydrolapachol resulting in the for- mation of hydroxyisolapachol and the isopropylfuran-naphthaquinones, is the only one suggesting itself which is in perfect accord with the whole of the facts accumulated in the study of the compounds of this group. Its acceptance would seem to be rendered necessary by the possibility of converting iso-P-lapachol into hydroxyisolapachoi and the isopropylfuran-naphthaquinones (pp. 1360, 1379), and also by the existence of the lomatiols and dehydrolapachone (see follomng paper), which hare most probably the following formulze respectively.1370 HOOKER : THE CO-\JSTITUTION OF LAPACHOL Lomatiol and isolomatiol. Deh ydrolapachone.Whilst the above changea are those occurring with concentrated eulphuric acid in the cold, there are yet others which are effected hy the somewhat dilute acid at the boiling temperature. In this case however, the principal product of the action is isopropylfuran- a-naphthaquinone, small quantities of hydroxy-a-lapacho)?e and anhydrodihydroxyhydrolapachol being simultaneously formed. The last two products are liere met with for the first time. The relation of hydroxy-r-lapachone to hydroxy-/3-lapachone is the same as that existing between a- and 6-lapachone, but the methods which are applicable for the conversion of a- into p-lapachone, and vice vers6, have failed to produce corresponding changes with the hydroxylapachones. Anhydrodihydroxyhydrolapachol is formed by the removal of one molecule of water from dihydroxyhydrolnpachol ; it has consequently the formula CISH,,Oa, being isomeric with the hydroxylapachones.Its structure is undoubtedly correctly represented as follows. I \)\/OH 0 This may be inferred from the following facts. I. Anhydrodihydroxyb ydrolnpachol dissolves in alkaline solutions readily, forms intensely coloured stable salts, and has the properties of a hydroxynaphthaquinone generally ; consequently the hydroxyl group attached to the naphthalene nucleus has not been disturbed. 11. It can be dissolved in concentrated sulphuric acid, and pre- cipitated therefrom unchanged. This proves the absence of the original hydroxyl groups attached to the second and third carbon atoms of the side chain, as in the presence of an hydroxyl group at either of these points, an internal anhydride would undoubtedly be formed by exposure to t.he action of the acid.Isoprop y &.wan-a-naphtha pinone. This compound was first prepared by heating dihydroxyhydro- lapachol in acetic acid Bolution with a small quantity of sulphuric acid. This method of preparation has its disadvantages, and as it was subsequently improved on, it is only given in detail here, because,ABD ITS DERIVATIVES. 1371 in addition to isopropylfuran-a-naphthaquinone, two secondary pro- ducts were isolated as the result of the action, which hare not yet been obtained as satisfactorily in any other way. Twelve grams of dihydroxyhydrolapachol mere dissolved in 200 C.C. of acetic acid, to which 5 C.C.of concentrated sulphuric acid, sp. QY. 1.84, had been previously added. The solution was boiled with a reflux condenser for 20 minutes, during which time it changed in colour from orange to greenish-brown ; it was then immediately poured into a large volume of cold water. A dark oily substance was precipitated, which soon commenced t o crystalli~e, and on the following day was readily filtered off. In addition to dark coloured resinous products, the crude substance consisted of a mixtiire of iso- propylfuran-a-naphthaquinone and another compound, fusing point 179*5O, which was subsequently proved to be acetoxy-a-lapachone. These compounds were sepa,rated by repeated crystallisation from alcohol, animal charcoal being a t first freely used. It was found after the resin had been removed by one or two crystallisations that isopropylfiiran-a-naphthaquinone, which crystallises very readily from sufficiently concentrated solutionP, first separated.It was thus obtained in heavy needles, from which the supernatant liquid, still retaining the larger quantity of the acetoxy-a-lapachone, was readily poured off. The solution on furhher standing, deposited both substances, acetoxy-x-lapachone predominating, however, in the mixture. A preliminary separation having been thus effected, no difficulty was encountered in subsequently completely purifying the compounds. The yield of isopropylfuran-a-naphtha.quinone amounted t o about 33 per cent., and that of acetoxy-a-lapachone to about 6 per cent. of the dihydroxyhydrolapachol employed.Isopropylfuran-a-naphthaquinone fuses a t l l O o , and, when abso- lutely pure, crystallises in canary-yellow needles, but as it is difficult to remove the last traces of colouring matter, the compound as usually obtained is apt to be light brown. From moderately impure solutions, the needles deposited are almost black, and frequently so much shortened that they appear as heavy grains. If a moderately concentrated alcoholic solution be rapidly cooled by immersion in cold water, care being taken not to agitate or otherwise disturb it, the solution apparently solidifies as the compound separates, in pale yellow, flattened needles, grouped together in globular masses, If now a few fragments of the crystals of the compound as ordinarily obtained be dropped upon the surface of the crystalline mass, they gradually increase in size and number at the expense of the more bulky variety, replacing i t entirely in the course of a few hours.This change is very striking and characteristic. Analysis gave the following figures.1372 HOOKER : THE CONSTITUTIOX OF LAPACHOL 0.1617 gave 0.4423 CO? and 0.0751 H,O. C1,H,,03 req5ires C = 75-00 ; H = 5-00 per cent. Isopropylfuran-a-napbthaquinone can be distinguished from all the remaining compounds so far obtained from lapachol by the colonr of its solution in concentrated sulphuric acid, which is intenselj crimson. On dilution, the substance is reprecipitated from the acid unchanged. Isopropylfuran-a-naphthaquinone is best prepared as follows. 600 C.C. of dilute sulphuric acid (one volume of acid, sp.gr. 1.84, and two volumes of water) are heated to boiling, and then transferred to a flask containing 8 grams of dihydroxyhydrolapachol. A few fragments of a porous tile, &c., are added to prevent the solution from becoming snperheated and obviate bumping. A reflux con- denser is then adjusted, the heating immediately resumed, and t,he solution kept briskly boiling for 15 minutes. Hydroxy-p-lspachone appears to be formed as the substance first dissolves, a clear orangc- red solution being obtained; as the action is continued, the liquid becomes turbid, an oil separates which grndually darkens, and becomes ultimately greenish-brown. After the boiling has been con- tinued for the required time, the solution is allowed to stand until the dark oily substance has conipletcly crystallised ; this is $hen col- lected,* washed, and digested for about 24 hours with a 1 per cent.solution of sodium hydroxide, in order to remove small quantities oE nnhydrodihydroxyhydrolapachol (compare p. 1378). The crude sub- stance is then purified by crystallisation from alcohol, the addition of mima1 charcoal being desirable. The weight of the purified substance approximates to about half of that of the dihydroxyhydrolapachol euiployed in its preparation. C = 74.59 ; H = 5.16. Acetox y- a- lapachone a d H y drox y- a- lap a choqae. The compound obtained in the preparation of isopropylfuran- a-naphthaquinone (p. 1371), cryst,allising from alcohol in pale yellow woolly needles, and fusing at 179-5", was analysed, with the following results.0.2044 gave 0.5072 CO, and 0,0993 H,O. C = 67-67 ; H = 5.39. 0.2058 ,, 0.5108 ,, ,, 0.0995 ,, C = 67.69; H = 5.36. C1,H1605 requires C = 68.00; H = 5.33 per cent. The formation of a compound of the formula CnH&j from dihydroxyhydrolapachol is i n part due t o the aclion of the acetic acid used as a solvent, Thus, * The sulphnric acid filtrate, in addition to isopropg lfuran-n-naphthaquinone and anhydrodihydroxyhydrolapachol, also contains small quantities of hpdroxy-u- lspachone.AKD ITS DERIVATIVES. 1373 I. C,,H,,OS = C,5H1401 + H,O. 11. C1,H,,O, + CH,3*COOH = C,,H,,(O*CO*CH,)O, + H,O. The dihydroxyhydrolapachol is thus first conrerted into an internal anhydride, which then Fields an acetyl derivative; the acetate is yellow, and is derived from the hitherto unknown hydroxy-a- lapachone The correctness of these conclusions was proved as follows.I. By the removal of the acetyl group and the isolation of hydroxy- a- 1 apachone. 11. By the reconversion of hydroxy-a-Iapachone into dihydroxy- hydrolapachol by the action of a boiling aqueous solution of sodium hydroxide. 111. By the reconrersion of the hgdroxy-a-lapachone into the acetate fnsing at 179.5' by the action of acetic anhydride. Acetoxy-a-lapachone dissolves in concentrated sulphnric acid, g i v i n g an orange-red solution from which, when freshly prepared, the addition of water reprecipitates the compound apparently unai - tered. The acid solution, on long standing, however, slowly under- goes a change, and eventually, after a week or two, becomes crimson in coloiir, doubtless owing t o the formation of isopropylfuran-a-naph- thaquinone. The conversion of acetoxj-a-lapaclione into hydroxy-a-lapachone cannot be accomplished by dilute caustic soda (1 per cent.), as it was fomd that in addition to effecting the removal of the acetyl group, the alkali simultaneously opened the side ring, converting the corn- pound into dihydroxyhydrolapachol. From the behaviour of the lapachones previously studied this was to have been expected.Whilst apparently pure, the dihydroxyhydrolapachol obtained did not fuse sharply even after several recrystallisations from alcohol ; arid the hydroxy-P-lepachone into which it was conyerted for further identification, whilst also apparently pure, fused through a com- paratively wide range.It is therefore probable that the dihydroxy- hydrolapachol contained a small quantity of its acetyl derivative. The acetyl group may be removed from acetoxy-a-lapachone by the action of dilute sulphuric acid. The strength of the acid is of importaiice, as if too weak, the hydrolysis does not occur, and if too strong, the hydroxy-a-lapachone first formed immediately undergoes further change, and cannot be isolated. After a number of experi- ments, it was found that good results may be obtained as follows.1374 HOOKER : THE CONSTITUTION OF LAPACHOL For 1 gram of acetoxy-a-lapachone, 150 C.C. of dilute sulp'nuric acid (1 volume of acid, sp. gr. 1.84, and 3 volumes of water) are used. The substance is ground, and then thoroughly moistened with a small portion of the acid, this being most readily done, by adding a drop or two a t a time, to the substance still in the mort8ar..It is then rinsed with a few C.C. of the acid, kept in reserve for the purpose, into the main portion previously heated to boiling in a vessel provided with a reflux condenser. The heating is continued for precisely six minutes from the time the solution recommences to boil, and if the substance has been carefully ground, it mill dissolve almost completely in this time. The solution is now cooled as rapidly as possible, and immediately filtered, being poured back, if necessary, until quite bright. Hydroxy-a-lapachone soon commences to separate in small, bright, yellow crystals, but crystallisation occurs slowly, and is complete after some hours only.2.02 grams of hydroxy-a- lapachone were obtained from 2.84 of the acetat.e. For purification for analysis, the compound was crystallised from alcohol, from which it separates slowly in a ricb, yellow crust con- sisting of numerous small rosettes, fusing at about 187". 0.1948 gram gave 0.4955 CO, and 0.0946 H,O. C = 69-37 ; H = 5.39. CI5Hl4O4 requires C = 69.76 ; H = 5.42 per cent. Hydroxy-a-lapachone was reconverted into its acetyl derivative as follows: 0.18 gram was mixed with 0.36 gram of dried sodium acetate, and boiled for a few minutes in a test tube with 5 C.C. of acetic anhydride. The liquid was then poured into water, and the oil which first separated soon solidified to a pale yellow, crystalline substance, which, after cry stallisation from alcohol, was recognised by its melting point, 179O, by its crystalline form and other proper- ties, to be the compound sought for.By the action of dilute alkalis, hydroxy-a-lapachone, like hydroxy- P-lapachone (Trans., 1892, 649) is converted into dihydroxyhydro- lapachol. 0.18 gram was boiled for a, few minutes with about 13 C.C. of 1 per cent. sodium hydroxide ; the substance dissolved readily to a claret coloured solution. Acetic acid was then added in slight excess. No precipitation occurred immediately, but yellow crystals separated slowly on standing, which were found to be identical in all particulars with t'hose of dihydroxyhydrolapachol. Hydroxy-a-la pachone dissolves in concentrated sulphuric acid in the cold to an orange-red solution. The addition of water discharges most of the colour, leaving the solution jellow, but does not cause the immediate formation of any precipitate ; unchanged hydroxy-a- lapachone separates, however, slowly on standing.Noderate heating with somewhat dilute sulphuric acid convertsAXD ITS DERIVATIVES. 1375 hydroxy-a-lapachone into isopropylf uran-cx-naphthaquinone, and for this reason it is necessary to carefully follow the directions given above in the preparation of hydroxg-z-lapachone from its acetate, otherwise the substance liberated will undergo this further change. 0.19 gram of hydroxy-u-lapachone was boiled with 10 C.C. of dilute sulphuric acid (acid sp. gr. 1-S4, 1 volume, water 2 volumes) for about seyen minutes. The substance dissolved to a clear, Sellow sohition, which soon became turbid.When cold, the partly crgstallised, brown deposit was filtered off and purified by crystallisation from alcohol. It was then recognised by its fusing point, 109*5', by the crimson colour with which it is dissolved in concentrated sulphuric acid, and by crystallising in the two characteristic forms, as isopropyl- furan-a-naphthaqninone. Hy&oz yisol apachol. When isopropylfurm - u - naphthaquinone is boiled with dilute caustic soda, the furfuran r i n g is opened, and hydroxyisolapachol is formed. The change does not take place as smoothly as in the con- version of the various lapachones into the corresponding hydroxyl compounds, and the action of the alkali is not so energetic. The operation was coiiducted as follows: 6 grams of isopropyl- furnn-x-naphthaquinone were boiled under a reflux condenser with 690 C.C.of a 1 per cent. solution of sodium hydroxide for. .nearly three hours. The substance first fused, then gradually passed into solut>ion, leaving a solid residue, consisting of a new compound, which did not appear t o be further attacked by the alkali. As the highly coloured aolution cooled, some unchanged isopropyl-furan- a-naphthaquinone separated? which had probably passed into solu- tion in consequence of the reduction of its qninone groiip, and which in proportion as air gained access to it was oxidised and reprecipitated." To complete the oxidation, air was drawn through the cold alkaline solution f o r two or three hours; the precipitate was then filtered off, and the filtrate acidified with dilute hydro- chloric acid.The hydroxyisolapachol which then separated as a curdy precipitate weighed, when dry, about 3.4 grams. Hydroxyisolapachol is very soluble in alcohol even when dilute. It separates from this solvent in yellow, silky needles, which, when pure, melt at 133*5-134°. 0.2311 gave 0.5893 COz and 0.1119 H20. C = 69.54; H = 5.38. CI5H,,Oa requires C = 69.76; H = 5.42 per cent. * The unchanged substance, mixed with the compound above referred to, was again submitted t o the action of sodium hydroxide, and this resulted in the further gain of a small quantity, about 0.65 gram, of hydroxyisolapachol.137 ri HOOKER : THE CONSTITUTION OF LXPACHOL It dissolves readily in dilute alkaline solutions, the colour pro- duced being intermediate in shade between the claret-red of lnpachoI and the orange-red of /3- hydroxy-a-naphthaqninone.T’he cautious addition of hydrochloric acid to a moderat,ely dilute alkaline solution causes the liquid to set to a pale yellow, jelly-like mass. Hydroxyisolnpachol is dissolved by concen tmted sul phuric acid to an orange-red solution, which almost instantly changes t o a brown, arid ultimately becomes a dark, dull red. 0.25 gram was dissolved in zbout 5 C.C. of concentrated sulphuric acid, which was allowed to act for about five minutes. The acid was then poured into water. When the resulting orange-red precipitate had become crystalline, the microscope revealed a mixture of yellow and red needles. These were separated by crystallisation from dilute alcohol, and were then I ccognised by their melting points, crystalline form, and coloui* re- actions with concentrated sulphuric acid as isopropylfuran-a- and iso- propylf uran-/3-naphthaquinone (see below) respectively.Isopropy ljtcran- P-napht haquiuone. If either dihydroxyhydrolapachol or hy droxyisolapachol be d is- solved in concentrated sulphuric acid, isopropylfuran-&naphtha- quinone is formed. I n both cases, howecer, it is only one (compare pp. 1368, 1369) of the products of the action, and hence its prepara- tion from either of the above substances by this method is tedious, and the yield small. If hydroxjisolapachol be reduced to the corresponding hydro- quinone, OH /\/\CH:C (OH) .CH <:z I I jOH 3 \/\/ *‘ OH the anhydride formation still takes place readily.The action, how- ever, under the conditions given below, is almost entirely confined to the hydroxyl group occupying the a-position in the naphthalene nucleus. The resulting compound can then be readily converted by oxidation into isopropylfuran-P-naphthaquinone. The operation is conducted as follows. 2-5 grams of hydroxyisolapachol is dissolved by the aid of heat in 100 C.C. in acetic acid, and 80 C.C. of water. 2.5 grams of zinc dust, followed by 40 C.C. of dilute hydrochloric acid (3 volumes water and 1 voluume acid, sp. gr. 1.20), are then added, and the solution is boiled under a reflux condenser for five minutes. The excess of zinc is next filtered off, and 0.65 gram of chromic acid dissolved in 25 C.C.XSD ITS DERIVATIVES. 1377 of water added.commence to separate shortly afterwards. melted sharply at 94-95?. Red needles of isopropylfuran-P-naphthaquinone For analysis, the substancg was recrystallised from alcohol until i t 0.2096 gave 0.5741 CO, and 0.0956 H,O. C,,H,,O, requires C = 75.0; I3 = 5.0 per cent. If a small quaiitilly of isopropylf uran-p-naph thaquinone be dissolved in a few drops of acetic acid, a deep, orange-red solution is obtained, which becomes intensely crimson on the addition of a few drops of concentrated sulphuric acid, and as the quantity of sulphuric acid is gradually increased becomes purple, and finally dark green. It is dissolved by concentrated sulphuric acid alone to a rich blue-green solution, from which water, if added soon afterwards, reprecipitates the substance essentially unaltered.The prolonged action of con- centrat ed sulphuric acid gradually, however, produces a change, resulting in the formation, amongst other prodnct,r;, of some isopropyl- f iiran - x-naphthaquinone. Pseudodehy drolapschone (Paternb's isolapachone), which is iso- meric with isopropylfuran-P-naphthaqninone, also develops almost exactly the same shade of green wit'h concentrated snlphuric acid ; it may, however, be readily distinguished by the fact that the green passes in a few minutes into a dark purple, whereas no such change occurs with isopropylfuran-,k?-naphthaquinone. The melting point of the two substances also differs widely, as pseudodehydroIapachone melts a t 140-141'. They can, moreover, be readily distinguished by their behaviour with dilute caustic alkalis ; in both cases acid substances are formed, but that obtained from isopropylfuran-p- naphthaquinone alone is stable, whilst that to which pseudodehydro- lapachone gives rise (compare Trans., 1892, 61, 623, 624), when liber- ated from its salts, immediately passes into its internal anhydride.Dehydrolapachone (see following paper), the red anhydride obtained by Rennie (Trans., 1195, 67, 792) from lomatiol, has also the formula C,,H1203, being isomeric with the above compounds, but its melting point, 11O-11lo, as well as the orange-red colour, passing into a brown, developed with concentrated sulphuric acid, serves to dis- tinguish it from them both. Isopropylfuran-P-naphthaquinone (0.50 gram) was boiled with a 1 per cent. solution of sodium hydroxide (50 c.c.) for about 30 minutes.The crystals fused to a red oil, which gradually decreased in quantity and darkened, until finally little besides small quantities of a, blue substance* remained undissolved. The alkaline solution was filtered off from this and acidified with acetic acid. The yellow, C = 74-70; H = 5.07. * This was found by microscopic examination to be distinctly crystalline.13713 HOOKER : THE COSSTITUTION O F LAPACHOL curdy, precipitate, consisting of microscopic tufts of needles, weighed 0.37 gram, and aQter crystallisation from dilute alcohol, was recognised by its melting point and other properties as hydroxyisolapachol. Isopropylfuran-P-naplithaquinone dissolves in concentrated hydro- chloric acid with difficulty, forming a purple solution.Under these circumstances, it is gradually changed, heing ultimately converted into the corresponding a-naph thaquinone compound. When action is allowed to take place in the cold, it is possible to demonstrate the presence of an intermediate product soluble in alkalis, and, doubtless, corresponding to chlorhydrolapachol, which was previously shown (Trans., 1892,61,621) to be formed by the action of hydrochloric acid on p-lapachone in its conversion into a-lapachone. The change can be readily effected i n an hour or so by digesting the substance in a relatively large quantity of hydrochloric acid, sp. gr. 1.20, at a tem- perature of about 75". The isopropylfuran-a-naphthaquinone obtained in this way possessed all the characteristics of that prepared as pre- viously described from dihydroxyhydrolapachol.Isopropylfuran-P-naphthaquinone, in virtue of its orthoquinone group, gives a characteristic azine with orthotolylenediamine, which crystallises in yellow, silky needles, and melts with decomposition a t about 132", darkening? and showing signs of fusion some degrees lower. The azine is coloured dark green by concentrated sulphuric acid, but the solution, when seen in sufficiently thin films, appears pink ; the addition of a small quantity of water precipitates a dull-red salt, which is decomposed on further dilution. The axine undergoes a change when its alcoholic solution is allowed to stand for a few days a t the ordinary temperature. The solution becomes darker, and exhibits increased fluorescence, depositing fluffy, orange-red crystals, which develop a csrmine colour with concentrated sulphuric acid.For much valuable experimental assistance in the preceding study of the dehydration of dihydroxyhydrolapachol, I am greatly indebted to MY. J. G. Walsh, junior, whose painstaking and careful work has greatly contributed to the successful conclusion of this research. A~tl~ydrodihydroxyhydrolapachol (compare p. 1370). This substance is formed in small quantity in the preparation of isopropylfuran-a-naphthaquinone from dihydroxyhydrolapachol. In order to isolate it, the latter, in its crude condition, is digested with a weak solution of sodium hydroxide (compare p. 1372). The alkaline extract is acidified with dilute hydrochloric acid, a n d the resulting precipitate purified by crystallisation several times from alcohol, animal charcoal being a t first used.The crude substance, previous to recrystallisation, amounted to only about 4 per cent. of the di- hSdroxy hydrolapach 01.AND ITS DERIVATIVES. 1379 Anhydrodihydroxyhydrolapachol crystallises in small, yellow tufts of short needles, which fuse at 190.5-191°, and dissolve in alkaline solutions with a rich crimson-red colour ; the substance is reprecipi- tated by acids in a distinctly crystalline condition. Like all the other lapachol derivatives previously studied, i t appears to be perfectly stable in alkaline solution ; even after boiling for about five hours with a 1 per cent. solution of sodium hydroxide, the substance had undergone no change. The folIowing analytical results were obtained.I. 0.1405 gave 0.3579 CO, and 0.0686 H,O. C = 69-47 ; H = 5-42, 11. 0.1638 ,, 0.4176 CO, and 0.0818 H20. C = 69.54; H = 5.54. CI5H,,Oa requires C = 69-76 ; H = 5-46 per cent. Anhydrodihydroxyhydrolapachol dissolves in concentrated sulph- uric acid to an orange-red solution, from which, water, if added soon afterwards, reprecipitates the substance essentially unaltered. If, however, the solution, previous to dilution, be allowed to stand for two or three days, the substance appears to be complctely changed, and a brown precipitate is then obtained, which differs in its pro- perties from anhydrodihydroxyh ydrolapachol, but still remains almost entirely soluble to a red solution in dilute alkalis. Conversion of Iso- p- lapachol into Isoproy y ljuran-p-n aphthaquinone.Seven grams of bromine, dissolved in 30 C.C. of chloroform, were gradually added to 10 grams of iso-P-lapachol, dissolved in 65 C.C. of chloroform. The bromine appeared to be completely absorbed, and the solution of iso-0-lapachol became lighter in colour as it was added. The chloroform was a t once distilled off from a water bath ; the residue, which was resinous, was taken up in 50 C.C. of alcohol. No perceptible quantity of hydrogen bromide passed over with the chloroform, hence an additive product had undoubtedly been formed. The alcoholic solution was allowed to stand eight days at the autumn temperature of the laboratory, during which time it darkened in colour, becoming intensely orange-red ; the alcohol was then partially distilled off.During the operation, hydrogen bromide and other pungent fumes passed over. When reduced to a small bulk, water was added to the solution ; the dark red resin precipitated was washed and then gently warmed with a small quantity of a 1 per cent. soh- tion of sodium hydroxide, to remove the traces of acid still present ; the substance shortly commenced to cry stallise. After standing over- night in contact with the alkali, i t was crystallised from dilute alcohol; 3.4 grams of beautiful red needles were obtained. The alcoholic mother liquor was concentrated, bnt, as no .further crystals separated, the substance in solution was again submitted to VOL. LXIX. 4,1380 CONSTITUTION OF LAPACHOL AND ITS DERIVATIVES. the treatment with 1 per cent. sodium hydroxide, above described. This resulted in a gain of an additional gram of the red needles; thus, in all, the yield of the pure substance amounted to 44 per cent. of the iso-P-lapachol used. For analysis, the substlance wsts again crystallised from alcohol. I. 0.2516 gave 0.6875 COz and 0.1111 H20. C = 74.52 ; H == 4.90. 11. 0.1489 ,, 0.4091 ,, ,, 0.0669 ,, C = 74.93; H = 4.99. C,,H,,Oa requires C = 75.00 ; H = 5.00 per cent. The substance has thus the composition C,5H,,0s, and is otherwise identical with isopropylfuran-/3-naphthaquinone. It melts at 94-95', dissolves in concentrated sulphuric acid with a characteristic blue-green colour, is converted by alkalis into hydroxyisolapachol, and by hydro- chloric acid into isopropylfuran-a-naphthaquinone ; it gives an azine with orthotolylenediamine, melting at about 132O, thus behaving in all particulars similarly to the isopropylfuran-/3-naphthaquinone described above, with which it is, beyond all doubt, identical. Various attempts were made to isolate the intermediate products in a pure condition, but these have not met with success. The crude substance, which is left in a resinous condition on the evapora- tion of the chloroform (see above), has doubtless the formula CloH4 CHBrGHBr*CH7. {:; This was treated with 1 per cent. sodium hydroxide in the cold ; it From the solution, impure dissolved slowly and almost completely. hydroxgisolapachol was precipitated by the addition of acids. The condensation of f3-hydroxy-a-naphthaquinone with isovaler- aldehyde, resulting in the formation of iso-P-lapachol, and the further change of the latter under the influence of bromine into a furfnran derivative of /3-naphthaquinone, which can then be converted into the corresponding derivative of a-naphthaquinone, would seem to justify the anticipation that we have in these reactions general methods, firstly, for the preparation of alkylene derivatives of hydr- oxynaphtha#quinone, in which the alkylene chain occupies the ,%position next to the hydroxyl group, and, secondly, f o r the conver- sion of these compounds into furfuran derivatives of both a- and P-naphthaqninone. This subject is also of interest as being likely t o furnish further material for general dednctions regarding the formation of internal anhydrides, and the conversion of ortho- into para- and of para- into ortho-quinone derivatives.HOOKER : LOMATIOL (HYDROXYISOLAPACHCIL). 138 1 In view of these possibilities, I have felt justified in undertaking a The results of my experiments will further study of these reactions. form the subject of a future paper. Philadelphia, U. 8. A .

ISSN:0368-1645    

DOI:10.1039/CT8966901355

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

HOOKER : LOMATIOL (HYDROXYISOLAPACHOL). 138 1 LXXXVII1.-Lomatiol (Hydroxyisolapachol). By S m u m C. HOOKER, IN an interesting paper published last year (Trans., 1895, 784), Rennie gives the resnlts of his study of the yellow colouring matter which surrounds the nuclei of the seeds of two species of the Australian lomatia, and expresses the belief that the compound is a, hydroxylapachol, recording, in support of his conclusions, its conver- sion into hydroxy-P-lapachone.* Dr. Rennic has very kindly for- warded to me small specimens of his substances, and a careful comparison enables me to confirm his conclusions, and to state positively that the hydroxy-P-lapachone received is identical with that previously obtained by me (Trans., 1892, 649) from dihydroxy- h ydrolapachol. Having established the intimate relation existing between lapachol and the lomatia colouring matter, Dr.Rennie suggested formuls for the various substances obtained in the course of his work, which were based upon what appeared to be at that time the most probable structure of lapachol. Since, however, it is now necessary to modify this (see preceding paper), corresponding changes must also be made in the structure of the lomatia compounds. To prevent confusion with the hydroxyisolapachol described in the preceding paper, I shall refer to the lomatia colouring matter as lomatiol. Since the formula of hydroxy-/3-lapachone must now undoubtedly be written O p - 1 and further, since lomatiol, C15H110d, when submitted to the action of concentrated sulphuric acid, appears to be first converted into an anhydride, C,,H,,Os, which, by the absorption of 1 mol.of water, becomes hydroxy-P-lapachone, it is evident that. the hydroxyl in the f The melting point of hydroxy-B-lnpachone previously given by me is, as Renuie ha3 surmised, too low. 4 2 21382 HOOKER : LOMATIOL (HYDROXYISOLAPACHOL). side chain of lomatiol must be attached to the same carbon atom, as are also the two methyl groups. The hydroxyl group being thus located, there is only one position possible for the double bond, namely, that between the first and second carbon atoms of the chain. We have therefore the following changes as the result of the action of conoentrated sulphuric acid. Lometiol, C15H1404* It is thus apparent not of lapachol itself. 0-, Dehydrolepachone, C15H1203. 0 Hy dror y-B-lapachone.that lomatiol is a derivative of isolapachol, C1SH1404* and By the action of a boiling aqueous solution of caustic potash on dehydrolapachone, the regeneration of lomatiol might be expected, but Rennie states that an isomeric hydroxylapachol, which may be called isolomatiol, is formed instead. This can probably be best explained by the supposition that the latter and lomatiol are stereo- isomeric compounds, and that lomatiol does not pass directly into dehydrolapachone, but is first converted into ieolomatiol, a. change which may be regarded as a necessary preliminaq to the anhydride formation. Thus H O*CioH,( 0,) *C *H H*C * C I o H 4 ( 0,) *OH II CH3 II CH3 H~C-CLOH - H.CG/OH ‘CH, \CH, Lomatiol. Isolomatiol. After making due allowance for the change in the structure of lapachol, the above interpretation of the facts which Rennie’s experi- ments have furnished differs in some minor details from that suggested by Rennie himself. The want of material unfortunately renders impossible an experimental inquiry as t o its Talue at the present time; the existence, however, of substances in the lapachol group isomeric with, but entirely distinct from, the lomatiol compounds, reduces the number of formula which might otherwise have been available, and gives weight to the relations suggested above.RUHEMANN AND WOLF: THE &KETONIC ACIDS, 1383 As Dr. Rennie has very kindly left to me the further investigation of these compounds, and has promised his assistance in securing the necessary material, I shall hope to return to the consideration of this subject in the future. Philadelphia, U.8. A.

ISSN:0368-1645    

DOI:10.1039/CT8966901381

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

RUHEMANN AND WOLF: THE &KETONIC ACIDS, 1383 LXXX1X.-Contributions to the Knowledge o f the ,&Ketonic acids. Part 11. By SIEGFRIED RUHEMANN, Ph.D., M.A., and C. G. L. WOLF, B.A., M.D. IN a paper recently published by one of us and E. A. Tyler (Trans., 1896, 69, 530), it was shown that the sodium derivative of ethylic acetoacetate readily reacts with ethylic chlorofumarate with the formation of a compound for which the formula C H,*C=y *COO CzH5 1 yR.cOOC,H6 O--CH*COOC2H, was brought forward. This constitution wat8 derived from the chemical and physical properties of the substance, and also from the fact that the same compound is produced by using ethylic chloromalente. It is, moreover, supported by the following con- siderations. If the interaction of ethylic sodioacetoacetate and ethglic chloro- fumarate were to take place as indicated by the equation C H3-C O*CHNa*COO C,H, + COC)C2H,*CH:C Cl*COO C2H6 = YOOC,H, NaCl + CH,GO~CH*~*COOC,H,, it might be expected that at the same time alcohol would be eliminated with the formation of tbe ethereal salt of a dicarboxylic acid, namely, ethylic methylconmalindicarboxylate.This conclusion would follow from the synthesis of the ethereal salt of isodehydracetic acid, which is brought about by the action of ethylic sodioacetoacetate on ethylic /3-chlorisocrotonate (Anscliiitz, Bendix, and Kerp, Annalen, 259,179), as indimted by the following symbols CO 0 C,H,.CH1384 RUHEMANN AND WOLF: THE @-KETONIC ACIDS. 7OOC2H5 Q H3 C H3*C 0 CHNa Cl*C:QH C,H50 C 0 v00C2H5 QH3 1 CH3Q:C--- C:QH 0 co The result of the action of the sodium derivative of ethylic aceto- acetate and ethylic chlorofumarate is, however, the ethereal salt of a tricarboxylic acid. The view of the constitution of this ethereal salt as expressed by the name ethylic methyldihydrofurfurantricarb- oxylate, is also supported by the experiments recorded in this corn- municat ion.Action of Ethylic Chlorofumarate on Ethylic Benzoylacetate. Forty grams of ethylic benzoylacetate are added to the solution of 4.8 grams of sodium in 100 grams of absolute alcohol, and 43 grams of ethylic chlorofumarate are then gradually introduced. A re- action sets in immediately, and is complete after an hour's heating on the water bath. On removing the alcohol by distillation, and adding water, an oil separates, which is taken up with ether.The ethereal extract is dried with calcium chloride, the ether evaporated, and the oily residue distilled in a vacuum. Almost the total quan- tity comes over at 242-245", under a pressure of 20 mm., as a yellow oil with a green fluorescence. The compound is very viscons, and does not solidify in a freezing mixture of ice and salt. It is insoluble i n dilute potash, and does not react with phenylhydrazine. On analysis, it gave numbers corresponding with the formula C,d%&%- 0.2252 gave 0.5206 CO, and 0.1128 H,O. C,,€T,,O, requires C = 62.98 ; H = 6.07 per cent. The compound resembles in its chemical behaviour the product of the interaction of ethylic sodioacetoacetate on the ethereal salts of chlorofumaric and chloromaleic acids, and i t may be regarded as ethylic phenyldihydrofurfurantricarboxylate, 1 QH*:.COOC,H5. Action of Potash.-Like the corresponding methyl compound, this ethereal salt is readily hydrolysed.By boiling the solution of the furfuran compound in alcoholic potash in a flask with a reflux con- denser on the water bath, a red oil collects at the bottom of the C = 63.04; H = 6.06. C 6 H 5 G ~ q * C 0 oc,H6 O--CH*CO OCZH6RUHEMANN AND WOLF: THE P-KETONIC ACIDS. 1385 vessel, which is undoubtedly the potassium salt of the acid. After four hours' heating, the alcohol is distilled off, and the residue treated with an excess of hydrocliloric acid, when carbon dioxide is evolved, and a crystalline precipitate separates, which increases on standing over night. The solid is collected on a filt'er, and the mother liquor, which still contains a small quantity of t,he substance, is extracted with ether.This compound readily dissolves in boiling water, and the solution, after being decolorised by animal charcoal, deposits, on cooling, bunches of colonrless needles, which melt with slight decomposition at 172', having begun to soften a few degrees lower. On analysis, the following numbers were obtained, corresponding with the formula CIzH1206. 0.2068 gave 0.4342 C02 and 0.0920 H,O. C12H,206 requires C = 57.14 ; H = 4-76 per cent. The hydrolysis of the furfuran compound leads also in this case to the formation of an acid, namely, acetophenylmalic acid, the consti- tution of which is to be expressed by the formula C = 56.98 ; H = 491.CeH6*C(OH):CHo7HCOOH CH(OH)*COOH. The silver saEt of this acid is obtained on the addition of silver nitrate to the solution of the acid neutralised by ammonia. For analysis it was dried first in a vacuum over sulphuric acid, and then at 100'. 0.2542 left on ignition 0.1176 Ag. The aqueous solution of the acid gives a white precipitate with lead acetate, which dissolves in water with great difficulty. Copper sulphate, when added to the solution of the acid neutralised with ammonia, throws down a bluish-green salt. A g = 46.86. ~ l z ~ l o ~ g 2 0 6 requires 46.35 per cent. Action of Ammonia on Ethylic PJ~enyldihydrofiLrfurantricar~oxylate. Ammonia reacts with this ethereal salt as it does with ethylic methgldihydrofurfurantricarboxylate. On allowing the ethereal salt to remain in contact with shong aqueous ammonia for three days, the contents of the vessel are transformed into n semi-solid mass of crystals, which readily dissolves in hot water, and, on cooling, comes down in long, thin needles, softening at 180' and melting at 185-186'.A nitrogen determination leads to the formula, C,,H,,N2Oa. 0.2194 gave 17.5 C.C. moist nitrogen at 16' and 759 mm. N = 9.28. CI~HI~N,O, requires N = 9.21.138tj RUHEMANN AND WOLF: TEE P-I(ETONIC ACIDS. The constitution of this compound is no doubt similar to that of the substance produced from ethylic methyldihydrofurfnrantricarb- oxylate, and is probably expressed by one of the following formulae : C,H,.?=Q.CONH2 C6H5* ?=?* COO C2H5 HT ~H*COOC2& or HT QH*CONH2. 0 C-CH*OH 0 C-CH*OH Action of the Sodium Derivative of Ethylic Methylacetoacetate on Bthylic Chlorofumarate.The interaction of ethylic chlorofumarate and the sodium derivs- tives of ethylic acetoacetate and ethylic benzoylacetate was explained by the assumption that the hydrogen atom of the a-hydrocarbon group, contained in the ethereal salts of these P-ketonic acids, shifts and brings about the closing of the ring in the following manner R*C=Q* C 00 C2H, clceCO CH*COOC,H54 0 C2H5 1 ~H*cooc2H6. R*$!:CH*C OOCIH, O--CH*COOC2H6 OH If this explanation be correct, it may be expected that by using the sodium derivative of ethylic acetomethylacetate instead of ethylic sodioacetoacetate, either the ethereal salt of a tricarboxylic acid of the formula CH,*C=C<CH, COOC2H6 I ,CH-COOC2H6 o-c'% 0 0 C2H, would be produced, or that the interaction of these substances would be accompanied by the splitting off of ethylic acetate with the formation of the compound which is to be regarded as ethylic methylfurfurandicarboxylate.That the reaction takes place in the latter manner is proved by experiment, and this fact affords a further support to the constitn- tion given above for the compounds formed by the interaction of ethylic chlorofumarate and the sodium derivatives of ethylic aceto- acetate and ethylic benzoylacotate. The reaction is carried out in the following way. Thirty grams of ethylic acetomethylacetate are mixed with a cold solution of 4.8 grams of sodium in 100 grams of absolute alcohol, and 43 grams of ethylic chlorofumarate gradually added, when theRUHEMANiS AND WOLF: THE /%KETONIC ACIDS. 1387 mixture turns deep red.On allowing it to stand over night, the cake of ethylic sodioacetomethylacetate disappears with precipita- tion of sodium chloride. The reaction is complete after about an hour’s heating at looo, the contents of the flask having a strong odour of ethylic acetate. On distilling on the water Lath, the ethylic acetate passes over together with the alcohol; water is added fo the residue, which throws down an oil ; this is taken up with ether, the solvent evaporated, and the remaining oil allowed to stand in a vacuum over sulphuric acid, when, after several hours, crystals separate and gradually increase in quantity. A certain amount of the same compound is still contained in the red aqueous solution, and may be obtained by adding an excess of hydrochloric acid and extracting with ether.The oil which is left, partially solidifies on standing in a vacuum. The substance obtained from the product of the reaction, before and after acidification, is collected on a filter, washed with benzene to remove adhering oil, and dissolved in hot., dilute spirit, from which, on cooling, i t separates in colourless plates, melting at 132O. The thick, yellow oil formed along with this substance does not deposit any crystals ; on distillation in a vacuum, it suffers decom- position, leaving a black mass in the distilling flask. It is a mixture of the f urfuran derivative of ethylic acetomethylacetate, ethylic chlorofumarate, and other compounds. Analysis of the compound melting a t 132’ gave the following numbers, which correspond with the formula for ethylic methyl- f nrfurandicarbox ylate CH,*C=$WOOC,H, I WH 0-C *CO 0 CzHs 0.2196 gave 0.4692 GOz and 0.1180 H20.C = 58.27 ; H = 5.9’7. 0.2136 ,, 0.4584 ,, ,, 0.1194 ,, C = 58.51; H = 6.21. CllHI4O5 requires C = 58.40; H = 6.19 per cent. The ethereal salt readily dissolves in alcohol and glacial acetic acid, but with difficulty in benzene. The alcoholic solution of the componnd is coloured red-violet on the addition of ferric chloride. The substance is soluble in ammonia and in dilute alkalis, and is reprecipitated unchanged from the yellow solution on the addition of hydrochloric acid. This behaviour explains why a certain amount of the furfuran derivative is contained as a sodium compound in the aqueous solution of the product of the interaction of ethylic chloro- fumarate and ethylic acetornethylacetate.The solubility of ethylic methylfurfurandicarboxylate may be attributed either to a splitting of the furfuran ring or to the negative characters of the -CH group.1388 RUHEMANN AND WOLF: THE @-KETONIC ACIDS. The &markable properties of the product formed from the ethereal salt on hydrolysis rendered it desirable to fix its formula by the determination of the molecular weight. (1.) 0.3468 gram dissolved in 23,309 grams of glacial acetic acid produced a depression of 0.25". @) 0,3884 gram dissolved in 24.671 grams of glacial acetic acid produced a depression of 0.26'. (3.) 0.7616 gram dissolved in 32.022 grams of absolute alcohol, distilled from sodium, increased the boiling point by 0.12'.(4.) 1.2256 grams dissolved in 33.6680 grams of absolute alcohol increased the boiling point by 0.18". Found. 7 Calculated for r-A- CllH1106. I. 11. 111. 1v. M ... ........ 0 . 226 232 23.3 228 232 Hydrolysis of Etliylic 3let72ylfu~furandica1.bozylate. The compound formed from the ethereal salt on hydrolysis is, on account of its remarkable properties, of considerable interest. Its study, which has occupied us for some time, led t o the following result. The hydrolysis of ethylic methylfurfurandicarboxylate is accom- panied by elimination of carbon dioxide, and yields a compound which, when dried at looo, has the composition C6H603, and this formula agrees also with the determination of its molecular weight.The sptbesis of this substance from the furfuran derivative would lead to the view that it is to be regarded as methylfurfuranmono- carboxylic acid, CH,*C=VH I riH 0-C *C OOH Its beharionr, however, as described below, points to the conclu- sion that it is to be looked upon a8 methylhydroxycoumalin, and that by the action of the hydrolysing agent on the ethereal salt at the same time, a destruction of the furfuran ring takes place as indi- cated by the followiug symbols CHs*C=QH CHs*CzVH -+ 1 6". 0 C*OH I 9= 0 C-COOH M ethylf urfurancarboxylic Methylhydroxycouma- acid. lin .RUHEMANN AND WOLF: THE B-KETOMC ACIDS. 1389 This anhydride exists only when the compound is dried at looo, or in solution in solvents free from water, such as acetone or absolute alcohol. In the presence of water, however, i t is partially trans.CH~.VI=YH formed into the dihydroxy-acid, OH tion of which decomposes barium carbonate dioxide. QH the aqueous soh- OOH' dOOH with evolution of carbon The analytical results lead to the view that in aqueous solution an equilibrium is established between the acid and its internal anhy- dride which is reached when the system has the composition 3(C6H804),C6H6O3 = 4C6Hf303 + 3H20, and which is also maintained in the air-dried substance. The hydrolysis of ethylic methylfurfurandicarboxylate may be effected by boiling the solution of the ethereal salt with a concen- trated aqueous solution of potash, or by heating it with hydrochloric acid. In the former case, the reaction is complete after three hours ; on addition of hydrochloric acid, carbon dioxide is evolved, and a crys- talline precipitate is thrown down, which increases 011 standing ; the mother liquor contains a quantity of the substance, which may be extracted by frequently shaking with ether.It is, however, more convenient to bring about the hydrolysis of the ethereal salt by boiling it with concentrated hydrochloric acid in a flask provided with a reflux condenser. The salt melts and gradually disappears ; after two hours' heating, a dark coloured solution is obtained which, on evaporation on the water bath, leaves a dark residue. This is dissolved in water, and the solution, after being decolorised by animal charcoal, deposits, on cooling, colourless prisms, which melt at 2pP" to a brown liquid.On drying the compoiind at looo, the crystals become opaque, and have then the composition C6H603, as indicated by the results of the following analyses, of which the first was made with a specimen obtained by hydrolysis with potash; the second by hydrolysis with hydrochloric acid. 0.2252 gave 0.4727 CO, and 0.0966 H,O. 0.2102 ,, 0.4384 ,, ,, 0.0950 ,, C = 56.88; H = 5.02. C6H603 requires C = 57-14; H = 4.76 per cent. The compound is insoluble in benzene and chloroform, readily The molecular weight of tohe componnd, dried at loo", was deter- C = 57.2 ; H = 4.76. soluble in alcohol and acetone. mined in solution in acetone with the following result.1390 RUHESIANN AND WOLF: THE P-KETONIC ACIDS. 0.5788 gram dissolved in 34.365 grams of acetone increased the boiling point by 0.19'.Calculated for c6IE603. Found. M . . .. .. .. .. .. .. 126 148 The solution of the coumalin derivative in absolute alcohol only slightly reddens blue litmus paper ; on addition of water, however, it becomes strongly acid. A solution of the compound in absolute alco- hol, when mixed with sodium alcoholate dissolved in alcohol, becomes deep red; the colour grows paler as water is added. These facts point to the conclusion that the product formed by hydrolysis of the furfuran derivative, when dried at loo", is not an acid, but becomes such in the presence of water. The acid, C6H804, is not stable, and readily changes into its anhydride, C6H& and this transformation partially takes place in aqueous soh tion and reaches an equilibrium, corresponding with the composition 3C6H8O4,c6H6o3, which is maintained in the air-dried crystals.We are indebted t o Dr. A. Hutchinson for the following crysta,llo- graphic examination. " System. Asymmetric. a : 71 : c = 1.1.925 : I : 1.2369. a = 94' 8', p = 104' 44', = 79' 3' " Forms observed : a( loo], b(oio), c(ooi), m(iio), a ( o i i ) , 40121, z(ro2). " Table of angles: Angle. 100 : 010 100 : 001 010 : 001 100 : 110 001 : 011 001 : 012 001 : 102 110 : 001 1.10 : 011 001 : 101 Measured (mean). Calculated. *lOOo 15' - TVIFi 46 - '88 34 - +55 5 - '49 46 - 31 15 30" 57)' 30 13 30 24 70 35 70 35 48 27 48 30& - 39 3 " The axial planes are well developed on these crystals which are often elongated in the direction of t'he Z axis. " The form (110) is nearly always present, and is sometimes large, the remaining faces, though of frequent occurrence, are small, and give poor reflections. " There is no wull marked cleavage.RUHEMANN AND WOLF : THE &KETONIC ACIDS.1391 " The extinction on b(010) in the obtuse angle @ is inclined 12" to " The extinction on ~(100) in the obtuse angle a is inclined 36F to the edge ah. the edge ab." The substance gives off the whole of the water at looo, no further The following determinations of the water were made with speci- 0.2098 gram lost on drying at 100" 0.0202 gram = 9.63 per cent. loss occurring at 110O. mens of different preparations of the air-dried substance. 0*3000 ,, 9 . ,, 0.0290 ,, = 9.66 ,, 0.2446 ,, 9 , ,, 0.0236 ,, = 9.65 ,, 0.3666 ,, 7 , ,, 0.0360 ,, = 9.55 ,, 0-4054 ,, $ 7 ,, 0.0398 ,, = 9.81 ,, 4CsH603,3H20 requires for transformation into 4C6Hs0, a, loss of 9.67 per cent.On titration of three different preparations of the substance, it was found that a solution of 0.3766 gram of the air-dried compound was neutralised by 20.7 C.C. of a solution containing 0.0037 gram NaOH in 1 c.c., which corresponds to 20.34 per cent. of NaOH. 0.3704 gram of the air-dried compound was neutralised by 21 C.C. of the same solution, which corresponds to 20.98 per cent. NaOH. 0.2766 gram was neutralised by 16.8 C.C. of a solution containing 0.0036 gram NaOH in 1 c c., which corresponds to 21-93 per cent, NaOH. 4CsH,03 + 3H,O requires for neutmlisation 21.46 per cent. NaOH. The acid does not form a stable salt with ammonia, for, on warm- ing, dissociation of the salt takes place, and the liquid becomes acid.A silver salt is not formed, as on addition of silver nitrate to the solution, rendered neutral with ammonia, reduction sets in, a silver mirror being deposited on the glass on warming. The acid de- colorises potassium permanganate and also reduces Fehling's solution, as does coumalic acid. The solution in alcohol turns deep red with sodium alcoholate, and, on adding ether, a reddish precipitate is thrown down, which is extremely hygroscopic. No precipitate is formed in aqueous solution by barium, lead: or zinc salts. The properties of this compound are interesting enough to deserve further investigation, which is in progress. Action of Ethylic Sodioacetoacetate on Ethylic a- Chlorocrotonate. This reaction was stndied with a view of ascertaining whether the 1 grouping fl'cooc2H6 of ethylic a-chlorocrotonate is negative enough CH*CHS1352 RUHEMANN AND WOLF: THE &ICETONIT: ACIDS.t,o cause a condensation similar to that brought about by the inter- action of ethylic sodioacetoacetate and the ethereal salts of chloro., fnmaric and chloromalexc acids, thiis giving rise to the formation of a compound of the formula 0--CH*COOC2E~ 'It was fonnd, indeed, that an ethereal salt of the composition C,,H,,O, is prodmced, the behaviour of which, however, seems to indicate that it does not possess the above const,itution. Of the two formule, which may be taken into consideration, the symbol (3) best explains the properties of the compound described below. The formation of such R substance would lead to the conclusion that the negative grouping of ethylic a-chlorocrotonate is not sufficient to transform the ketone group of ethylic acetoacetate into the ethenol group.The action may be regarded as proceeding first with formation of , which, in the second phase of the reaction, CH,*CO *YH*COOC,H, CH,*CH:C*COO.C&f, suffers a molecular transformation, accompanied by a condensation t o the ring compound, ethylic methyldihydrofurf urandicarboxylate. 29.6 grams of ethylic a-chlorocrotonate are added to a solution of ethylic sodioacetoacetate, obtained by mixing 26 grams of ethylic acetoacetate with 4.6 grams of sodium in 100 grams of absolute alcohol. The mixture is boiled on the water bath in a, flask with a reflux condenser until i t shows only a slight alkaline reaction to litmus ; this point is reached after three or four hours' heating.The alcohol is then evaporated, water is added to the residue, the oil which is thrown down is extracted with ether, and, after removal of the ether, distilled in a vacuum. It boils at 16O-Ici2" under a pressure of 16 mm., and has the density d 19'/19" = 1.0986. The following analytical numbers agree with the formula C,,H,,05. 0.2296 gave 0.5024 CO, and 0.1538 H20. CizH,,O, requires C = 59.50 ; H = 7-43 per cent. The molecular refraction does not enable us to decide between formula (1) or (3), on the one hand, and (2) on the other, at the values lie close together. They are for the expression C12H180"20 <I= = 60.76 and for C,2Hl,0"302<l' = 60.58. The ethereal salt is prepared as follows.C = 59.62 ; H = 7.43.RUHEMANN AND WOLF: THE P-KETOXIC ACIDS. 1393 Mr. A. S. Hemmy, of St. John's College, bad the kindness to deter- mine the refractive index of the compound, and found it to be nNo = 1,464 at 22". amounts, therefore, to n2 -1 (ns + 2)d' The molecnlar refraction, M 60.78. The chemical behaviour of the compound, however, pointp to the formula (3). The ethereal salt is insoluble in alkalis; it does not react with phenylhydrazine ; it evolves hydrogen bromide on the addition of bromine, as does ethylic methyldihydrofurlurantricarb- oxylate. The action of the halogen on the ethereal salt is accom- panied by an evolution of heat which renders the use of carbon tetrachloride as a diluting agent advisable.The yellow oil which remains after removal of the carbon tetrachloride, suffers partial decomposition on distillation in a vacuum. A bromine determination of the product, which had been heated to 150' under reduced pres- sure and allowed to stand in a vacuum over potash and sulphuric acid, gave 26.14 per cent. of Br. This value indicates that the formula of the bromo-derivative is ClzH1,BrOa, which requires 24.92 per cent. Br. These properties of the compound seem to exclude the constitution represented by the symbol (2), and the behaviour towards ammonia points to formula (3). Action of Ammonia-The ethereal salt, when allowed to remain in contact with a concentrated aqueous solution of ammonia, gradually disappears, while crystals separate. The reaction is almost complete after th:ee to four days, when the solid is collected. This dissolves in boiling water, and, on cooling, separates in colourless plates, which melt Itt 169-170°, and have the formula C,oH1,NOa. 0.1999 gave 0.4134 CO, and 0.1276 HzO. 0,2680 ,, C,oH,5NOt requires C = 56.24; H = 7.04 ; N = 6.57 per cent. From the composition of this substance, it follows that the action of ammonia on the ethereal salt yields a monamide, which may be represented by one of the following two expressions. C = 56.40 ; H = 7.09. 16.0 C.C. moist nitrogen a t 25'and 758mm. N = 6.64. CH,'CZF*CONH, CH,*C=v*CO OCzHs I FH.COOC,H, or 1 YH-CONH~. O--CH*CH, O-CH.CH, The behaviour of ammonia towards the product resulting from the action of ethylic sodioacetoacetate on ethylic a-chlorocrotonate differs, therefore, from that of ammonia on the compounds formed from ethy c chlorofumarate and the sodium derivatives of ethylic aceto- aceta e and ethylic benzoylacetate. I n these cases we have to assume the opening of the furfuran ring with accompanying condensation to1394 RUHEMANN : FORMATION OF PYRAZOLONE DERIVATIVES pyridine derivatives, which we should also expect if the compound Cl2HI8O5 had the constitution (1). These considerations lead, thus, to the formula C H3.7 =y*C 0 0 C2 H, 0 CH*COOC,H, \/ CH*CHS for the ethereal salt. The rea~on why this compound showa 8 greater stability is most probably to be found i n the positive character of the groups with which the -0- atom of the furfuran ring is united. The product formed on hydrolysis of the ethereal salt is still under examination. Gonville and Caius College, Cam. bridqe.

ISSN:0368-1645    

DOI:10.1039/CT8966901383

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

1394 RUHEMANN : FORMATION OF PYRAZOLONE DERIVATIVES XC. -Formation of Pyrazolone Derivatives from Chlorofumaric: acid. By SIEGFRIED RUHEMANN, Ph.D., M.A. CLAUS and Voeller (Ber., 1881, 14, lsl), and W. H. Perkin, senior (Trans., 1888, 53, 702), by the action of ammonia on ethylic chloro- fumarate, obtained, in addition to ethylic chlorofnmaramate, the diamide of amidofumaric acid. The readiuess with which the chlo- rine atom of the ethereal salt is replaced by the nmido-group, rendered it probable that hydrazine would also effect a similar snb- stitution, and a t the same time bring about a condensation to a pyr- azolone compound. Such a change does, in fact, take place, and gives rise to the formation of ethylic 5-pyrazolone-3-carboxylate, as represented by the equation COOC2H~*CH:CCl*C00 C2H5 + SNH,*NH, = C OOCJ€5.$-7H2 N GO ‘4H + CZHCO + NHZ.NH2,HCl. This substance is identical with the compound which v.Rothen- burg (J. pr. Chem., 1893, 51, 53) obtained froin the ethereal salts of oxalacetic azld acetylenedicarboxylic acids. We have, therefore, to assume that the condensation of ethylic chlorof amarate and hydr- azine hydrate to the pyrazolone derivative is accompanied by a mole- cular transformation similar to that which brings about the formation of ethylic 5 -pyrazolone-4-carboxyla te from e thy1 ic dicarboxyglu ta- conate and the hydrazine (Ber., 1894, 27,1658 ; lS9.5, 28, 987).FRO31 CHLOHOFUXXRIC ACID. 1395 The action of hydrazine hydrate on ethylic chlorofumarate pro- ceeds with great development of heat. The product, 011 cooling, sets to a mass of crystals if the reagents are employed in the proportion of 1 mol.of the ethereal salt to 2 mols. o€ hydrazine hydrate; but, in using an excess of the base, no solid separates until the liquid is neutralised with hjdrochloric acid. The crystals are collected, and dissolved in boiling water, from which, on cooling, colourless needles separate, softening a t 180" and melting a t 184--155O. They are readily soluble in alcohol and ether, and their. aqueous solution is coloured red by ferric chloride. The following analytical data corresporid with thc formula, C,€r,N,O,. 0-2500 gave 0.4220 CO, and 0.1116 H20. 0.2i94 ,, 40 C.C. moist nitrogen at 22" and 762 mm. N = 17.87. C,H,N,O, requires C = 46.15 ; H = 5.12 ; N = 17.94 per cent.For identification, the compound obtnined by v. Rothenburg was prepared from ethylic oxalncetate. This product gives the same reactions, and melts at the same temperature as does the substance produced from ethylic chlorofumarate, whilst v. ltothenburg gives the melting point 1 7 9 O , and states that the ethereal salt is almost illsoluble in water. Besides ethjlic 5-pyr~zolone-3-carboxylate, there is formed a com- pound which is very readily soluble in water, and is contained in tbe mother liquor from the pyrazolone derivative. This reduces Fehling's solution, and crystallises from concentrated aqueous solu- tion in plates decomposing at about 236'. It was not further examined, but there can be no doubt that it is identical with tho substauce formed along with ethylic pyrazolonecarboxylate from the ethereal salt of oxalacetic acid, which v.Rothenburg characterised as py razol 011 e- 3- carbony l h y dr azi n e . E th ylic pyrazolone-3-cnrboxylate dissolves readily in potash and in ammonia ; its solutioii in water, after being neiitralised with ammonia, yields, with silver nitrate, a white precipitate; this is washed wit11 water and dried a t 100'. Analysis of the silver compouud proves it t o have the formula CaHsAg,N20,. C = 46.03; H = 4.96. 0.3810 left on ignition 0.2218 Ag. Ag = 58.21. CaH6Ag,N2O3 requires Ag = 58.38 per cent. The hydrolysis of the ethereal salt is brought about by boiling its solution in potash, and is complete after two hours' heating. On addition of an excess of hydrochloric acid to the alkaline liquid, the pyrazolonecarboxylic acid is thrown down ; this dissolves in boiling water, and, on cooling, separates i n microscopic plates.On account VOL. LXIX. 5 A1 396 RUHEMANN : FORJIATIOS OF PTRAZOLONE DERIVATIVES of the difficulty with which the acid dissolves in water, there is no danger of its becoming contaminated with inorganic matter, as v. Rothenburg (loc. c i t . ) states to be the case if potash is used as the liydrolytic agent. The acid, prepared according t o the above direc- tions, burns away without leaving a trace of ash, and, on analysis, gives nnmbers closely agreeing with the formula C,H4N,0,. 0.2238 gave 0.3062 C02 and 0.0658 H,O. 0.2386 ,, 46 C.C. moist nitrogen at 25' and 765 mm. N = 21.64. C~H4N203 requires C = 37.50; H = 3.36 ; N = 21.87 per cent.The acid does not melt, but begins to decompose a t about 260' ; its C = 37-31 ; H = 3.26. aqueous fiolution becomes violet on addition of ferric chloride. Action of Phen ylhydraziiie 09% Ethylic CJilorofuma~ate. Whilst the interaction of hydrazine hydrate and ethylic chloro- fumarate is accompanied with development of heat, no perceptible change takes place on mixing the etheyeal salt with phenylhydrazine, and, even on allowing the mixture to stand a t the ordinary tew- perature for several days only a small quantity of phenylhydrazine hydrochloride separates. Reaction, however, takes place more readily on heating the mixture on the water bath for a few hours. The product is then allowed to cool, and, after addition of ether, t,he ilydrochloride of phenylhydrazine is filtered off.On removal of the ether, an oil remains which does not solidify, but, when heated in an oil bath at 170', yields, in addition to a resin, a sparingly soluble, crystalline substance. Their separation may be effected by digesting with alcohol, which dissolves the resin, leaving the white solid behind. This is soluble with difficulty in boiling glacial acetic acid, and, on cooling, scparates in colourless needles which melt and decompose at 272". Analysis of this substance gave numbers corresponding with the formula C24H22N40s. 0.2068 gave 0.4i06 C02 and 0.0936 H20. C = 62.06 ; H = 5.02. 03226 ,, 0.5078 ,, 0.1024 ,, C = 62.19; H = 5.11. 0.1266 ,, 14 C.C. moist nitrogen at 24' and 758 mm. N = 12.36. CwH,,N40, requires C = 62.33; H = 4.76; N "'- 12.12 per cent.The compound dissolves in potash and in ammonia, forming yel- low solutions ; the ammoniacal solution, on addition of silver nitrate, jields a precipitate which darkens on warming. The product gives the pyrazole-blue reaction with ferric chloride, bromine water, or potassium nitrite. The reagents are to be added carefully to the substance suspended in acetic acid, as au excess of the reagent destroys the colour. These properties characterise the compound asFROM CHLOROFUblARTC ACID. 1397 a pyrazolone derivative, and it is to be looked upon as the ethereal salt of bis-phenylpyrazolonecmboxylic acid, N CO CO N C 00 C2H5* H-Q H - f C 00 CZH, The formation of this ethereal salt may be interpreted by assuming that at first partial transformation of ethylic chlorofumarate into ethylic pheriylliydrazofnmarate takes place, which then, under the oxidising influence of phenylhydrazine, suEers a condensation to the bis-pyrazolone compound. Ethylic phenylpyrazolone-3-carboxylate, which W. Wislicenus (Annulen, 1888, 246, 320) obtained from ethylic oxalacetate, might have been expected to be formed, but could not be isolated. I must express my thanks to Dr. Wolf, of Mc.Qil1 Universitj, for help afforded me in the course of the above experiments. Gonrille and Cniics College, Cambridge.

ISSN:0368-1645    

DOI:10.1039/CT8966901394

出版商:RSC    

年代:1896

数据来源: RSC

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FROM CHLOROFUMARTC ACID. 1397 XCI.-Stzcdies of the Terpems and allied Compounds. Note on Ketopinic acicl-a product of the Oxidation of the solid Hyclrichloi-ide ( Clzloyocanaphydrene) prepared from Pinene. By HENRY E. ARNSTRONG. NOTWITHSTANDING the amount of attention lavished on the study of the terpenes and allied compounds, we are still unaware of the genetic connection subsisting among the greater number ; in fact, i t cam scarcely be definitely asserted of any one of them that we know its constitution : the argnments made use of too often involve assump- tions, the acceptance of which-requires an excess of credulity not easily exercised. The protean transformations to which they give rise are truly re- markable ; in no other group is such extraordinaxy plasticity notice- able; but this fecundity is a soarce of perplexity, and, in a measure, the bane of progress, however gratifying to the vanity of the worker anxious to associate his name with the preparation of new compounds.The group is apparently one altogether peculiar in type, and t h e difficulty of arriving at final decisions is greatly enhanced by the VOL. LXIX. 5 B1398 ARMSTROXG : STUDIES OF THE TERPENES fact that hitherto our studies have Been entirely analytical; syn- thetical observations calculated to give fixity to our opinions are sorely needed. But in ultimately solving the problems which the terpenes and their congeners present, we shall undoubtedly enormously in- crease our knowledge of chemical processes, and more especially of a class of operations of great biological significance ; hence the import- ance of not relaxing our efforts. Among the many interesting educts to which terpenes give rise, perhaps the most striking of all is the solid hydrichloride obtained by the interaction of terebenthene or pinene and hydrogen chloride ; its extreme stability especially is very remarkable when the readi- ness with which it is produced is taken into account.Although prepared directly from pinene, i t is open to question whether it be an immediate derivative of that hydrocarbon ; indeed, its properties are such as clearly to suggest that it is related more closely to cam- phene than to pinene. In any case, we are not at present justified in terming it pinene hydrochloride, and as it is obviously closely related to the saturated camphene-like hydrocarbon, CI0Hl8, into which i t is converted by the action of sodium, which may conveniently be termed camphydrene, I propose to speak of it provisionally as chlomcamphydrewe.It is very noteworthy, as I have pointed out in a recent note in the Pyoceedings (1896, 161, 44) on the relation of pinene to citrene, that whereas chlorocamphydrene is highly active, the dibro- mide and nitrosochloride prepared from pinene are both optically in- active. Such differences in optical characters are deserving of greater consideration than they have hitherto received if, as there is every reason to suppose is the case, inversion of optical actirity can only be conditioned by the occurrence of change immediately within the sphere of activity of an asymmetric carbon atom.It is, in fact, probable for this reason that the dibromide and nitrosochloride are not mere products of the addition of Br, or NOCl respectively to pinene, and that their formation involves a change in which the asymmetric carbon atom i n pinene is involved. To repeat what I said in the note in question- '' It is to be remembered that the carbon atoins which are connected by an ethe- noid linkage in pinene cannot be the origin of its optical actirity, and that, what- ever it may be, its formula must be one containing at least one asymmetric carbon atom. But, this being the case, it is diEcult to understand how the addition either of bromine or of nitrosyl chloride can give rise to optically inactivz products capable of affording an inactive pinene ; the occurrence of '' racematisation" in such a case would seem to indicate that the region in which thc asymmetric carbon is situated also becomes affected, although, apparently, but temporarily : i.e., what- ever be the change, it is subsequently reversed-even when pinene is converted into the nitrosochloride.Jf we cannot accept this conclusion, we must admit thatAND ALLIED CdMPOUNDS. 1399 the formulze hitherto attributed to pinene are all unsatisfactory expressions to a far greater extent than we have ever supposed. The difficultv: it may be added, is greater in the case of such a formula as Tiemann'e-as this contains two asymmetric carbons-than in the case of those proposed by v. Baejer, or by the writer." If the argument of the following note (reproduced below)? be admitted, the production of an inactire " A similar argument is ayplicable in the case of camphor.* The possibility of pinenc being a trimethylene derivative was cofisidered in the uote in question ; the formula given by way of illustration--as the simplest ex- pression of such a view-was the following. H2C-C?H2 v CH f '( The Conditions invo7ved in the occurrence of Incersion in the case of Asym- metric Optically Active Compounds.-Having formed the opinion that the changes which attend the production of what are supposed to be pinene derivatives merit much closer attention, the writer has been led to carefully consider Walden's recent very remarkable observations on the formation from each of the two active malic acids by means of phosphorus pentachloride or bromide of an oppositely active chloro- or bromo-succinic acid, from each of which in turn a malic acid of its own order of activity may be obtained (Ber., 1896, 133).It does not appear dificulb to explain these results without any modification of our current theory, and attention is now called to considerations which, perhaps, may prore to he of importance in discussions of the behaviour, and of other questions relating to, asymmetric compounds. 6' When optical inversion is effected by hydrolytic agents, in the case of either an aldose or a ketose or acid, it is probable that, in the first instance, the keto-group becomes hydrated, and that either an ' aldehydrol,' CH(OH),, 01' a ' ketohydrol,' C(OH)2, or an 'acidhydrol,' C(OH)B, is produced.When water i s withdrawn from such compounds, if the water be formed from an OH group of the hydro1 complex and a hydrogen atom attached to the carbon contiguous to that of the hydro1 complex, an ethenoid derivative will be formed, thxs CH'*OH CH-OH C*OH I + OH2 = = II + OH;. CO*OH C(OH)3 C(OH), "'On hydration, according as hydration takes place a t the one or the other junc- tion of the ethcnoid linkage, such acompound will afford one or the other of the two possible asymmetric forms ; and if, as in the case of tartaricacid, the compound be symmetrical, i t is to be expected that the two forms will be produced in equal proportions. But if an unsymmetrical compound be thus changed, such as a hexose or an acid like giwonic acid, it is to be expected that the severance will take place to a greater extent at one of the two junctions, and in some cases, per.haps, only at one. The striking results recently obtained by Lobry de Bruyn, and all E. Fischer's Observations, are in accordance with this view, which, in fact, is the generally accepted one. '' When malic acid is acted on by, say, phosphorus pentachloride, probably the campholide on reduction of camphoric anhydride (Haller, C. R., 1696, 295) may, 5 B 21400 ARMSTRONG : STUDIES OF TIIE TERPEKES in fact, be regarded not only as a proof that the CO group undergoing reduction is connected with a hydrogenised asymmetric carbon atom, but also as eridence of the presence of but a single asymnietric carbon in caniphor.” Taking the evidence afforded by optical characters into account, the argument here used would justify the conciusion that the hydri- chloride rather than either the dibromide or the nitrosochloride is an immediate derivative of piuene; and yet, apparently, the two last are alone reconvertible into pinene.Attempts that I have made from time to time to obtain derivatives from chlorocamphydrene have a.lways been failures. Many years ago I succeeded in oxidising it by prolonged digestion with dilute nitric acid, but the results were unsatisfactory both as regards quality and quant.ity of product’ ; owing to the difficulty of securing contact be- tween the acid and the chloride, the action took place with extreme slowness, and it was impossible to prevent fnrther oxidation of the immediate product. It is noteworthy, however, that a minute quan- tity of camphoric acid was obtained in these experiments-a fact which was referred to under camphoric acid in the 1880 edition of the organic part of Miller’s Chemistry, prepared by Mi*.Groves and myself .* first action to occur is one involving the formation of a chlorophosphonium com- pound, thus (1) CHeOH + PCl, = C H - O h l , + HCI. a b “The nest stage in the change may be assuined to be one involving ( internal condensation.’ h + HCl. a b 0 c<h, (2) CH*OPC14 = cc “Supposing that this compound be then acted on by hydrogen chloride and resolved into cblorosuccinic acid and phosphorus oxychloride, if the attack became directed by the phosphorus, so that the chlorine took up the position of the phos- phorus, complete inversion mould be effected.? b 0 a b (3) C<hcl, + HC1 = CClH + POCl3.a ‘‘ It will be obvious that such an explanation may be of general application, especially in connection with the exclusive production, under natural conditions, of a single asymmetric form.” * ‘( Dextrocamphene from the monohydrochloride from American turpentine yields a dextrorotatory camphoric acid having similar properties, which apparently is also produced on directly oxidising the moiiohy drochloride prepared from American turpentine with nitric acid (Armstrong).” thereby be brought into position b. t The result n ould be the same if tlie oxygen exercised the orienting effect, as the hydrogen wouldAND ALLIED COMPOUNDS. 1401 The discovery that the very strongest nitric acid could be used with advantage in oxidising dibromocamphor made in my laboratory by Dr.Forster, induced me again to attempt the oxidation of chloro- camphydrene, substituting such acid-in which i t readily dissolves- for the diluted acid previously used. Experiments made at my sugges- tion by two of my students, Messrs. W. S. Gilles and F. F. Renwick, have been rewarded with success, and have led to the diacovery of a remarkable acid, which apparently has not been previously obtained ; as it exhibits ketonic functions, and is indirectly derived from pinene, it is proposed to term it ketopiytic acid. Messrs. Gillcs and Renwick find that great care must be exercised in effecting the oxidation, as if the temperature be allowed to rise to 30" or 40", only oxalic acid is produced, whilst if it fall to 17' or 18O, the action does not take place ; the hydrichloride should be added (1 part) to the acid ( 5 parts) at such a rate that the acid is main- tained at a temperature as near to 20' as possible.After 48 hours the acid solution is poured into several times its bulk of water, and the liquid is after wards neutralised with chsl k sludge. The separation of the acid is facilitated by the fact that i t farms a sparingly soluble calcium salt the solubility of which is not increased by heating ; consequently, on evaporating the solution, the salt sepa- yates first along with some calcium nitrate, which is removed by digesting the crude salt with dehydrated spirit. The acid may be obtained by adding the calculated quantity of oxalic acid to a solu- tion of the calcium ealt, and subsequently concentrating the liquid ; i t separates as an oil, wliich solidifies on cooling.The amount obtained is equal in weight to about 10--15 per cent.. of the hydri- chloride used. Hetopinic acid crystallises from water in colourless plates melting at 234' (uncorr.) ; but, in contact with water, it melts below 100'. Although sparingly soluble in water and light petroleum, it is very soiuble in alcohol, benzene, chloroform, ether and ethylic acetate, and crystallises well from the last mentioned of these. It is opti- cally inactive even when prepared from the most highly active h y drichloride. The methylic salt is very soluble in all ordinary solvents except water ; when purified by distillation, it forms a colourless mass melting at 28O.The baric and calcic salts, which are sparingly soluble in waterand insoluble in alcohol, separate in white needles on evaporating their aqueous solutions. On digesting a solution of the acid in acetic acid with phenyl- hydrazine, a liydrazone was obtained, which, after recrystsallisatiofi1408 STUDIES OF THE TERPENES AXI) ALLIED COMPOUNDSc from acetic acid, fused sharply at 146' ; it was soliible in a solution of sodic carbonate. The corresponding hydroxime was obtained by warming a solution of the acid in a slight excess of caustic soda, with liydroxylrtmine hydrochloride. This mas almost insoluble in water and light, petr- oleum, but readily soluble in alcohol, acetic acid, chloroform and ethylic acetate. It fused at 216'. Bromine was without action on the acid. The analyses which have been made of the acid and its educts justify the forrriula C,oH,403, thus Found. Calculated. Acid.. . . . . . . .. C 65.97, 65.96, 65.90, 65.70 65.93 H 7-72, 7.48, 8.8, 8.13 7-69. Methylic salt . . C 67.17, 67.06, 67.29 67.35. H 8.41, 8.44, 8.20 8.16 Baric salt . > . . . B8 27-4 27.4 Calcic salt . . .. H20 3.6 1 mol. 4.3 Ca 9.90 9.95 Hydrazone . . . . N 10.40 10.30 It is proposed to fully investigate ketopinic acid, and to apply the method used in its production to other derivatives of terpenes, &c., containing halogens ; experiments made with pinene nitrosochloride have hitherto been unsuccessful. Hpdroxime., . . N 7.66, 7.41 7-21 Chemical Department, Central Technical College, City and Guilds of London Institute.

ISSN:0368-1645    

DOI:10.1039/CT8966901397

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

1403 LOTHAR MEYER MEMORIAL LECTURE. By P. PHIILLIPS BEDSOS, M.A., D.Sc., F.I.C. WE meat this evening a t the invitation of the Council of this Society to contemplate the life and work of a man who, little more than year ago, passed away after a sudden and painless attack, and thus would we pay our homage to the memory of one who has in so great H variety of ways contributcd to the advancement of the science, the fostering and promotion of which me a11 have at heart. The chronicles of the liFe of a man of science are usually of 5t simple character, presenting to all, save those who either enjoyed his personal friendship or have a special interest in the scieutific work of the individual, little of apparent note. But for us, as Fellows of R Society which has lost one of its most d i s h p i s h e d members, and to marly of whom he stood as friend and fellow student, and to the majority as guide and instructor in the fundamental theories and facts of our science, no one item of the chronicle of the life of Lothar Meyer can fail to be of interest.Julius Lothar Meyer was born on the 19th of August, 1830, at Varel ou the Jade, in the Grand Duchy of Oldenburg. His father, Dr. Friedrich August Meyer, was in practice as a medical man in that town ; and his mother, Frau Anna Sophie Wilhelmine, ne’e Biermann, also a native of this same place, was the daughter of a medical man who, during his lifetime, was highly respected and esteemed, and whose memory was cherished in Varel for many years after his death. Lothar Meyer’s mother was an only child, the constant companion of her father, and imbibed from him a love for the pro- fession, which enabled her not only t o enter fully and sympathetically into the labours of her husband, but often-despite her feeble health -to lend assistance in surgical operations.These facts, together with the respected position which their father held, readily explain how Lothar and his brother, Professor Oskar Einil Meyer, should, at the outset of their careers, have decided to follow medicine as their life’s profession. But, fortunately for science, this decision was not carried to its ultimate isaue ; by one brother, medicine was forsaken for chemistry, and by the other for the sister science of physics. Lothar Neyer’s early education was received at a small private school, and from thence he passed t o the recently founded “Burger- schule,” in Varel, at which he remained until his fourteenth year, receiving, meanwhile, private izlstruction in Latin, Greek, and the niodern languages.His rapid growth and consequent delicate health1403 LOTHAR MEYER MEMORIAL LECTURE. By P. PHIILLIPS BEDSOS, M.A., D.Sc., F.I.C. WE meat this evening a t the invitation of the Council of this Society to contemplate the life and work of a man who, little more than year ago, passed away after a sudden and painless attack, and thus would we pay our homage to the memory of one who has in so great H variety of ways contributcd to the advancement of the science, the fostering and promotion of which me a11 have at heart. The chronicles of the liFe of a man of science are usually of 5t simple character, presenting to all, save those who either enjoyed his personal friendship or have a special interest in the scieutific work of the individual, little of apparent note.But for us, as Fellows of R Society which has lost one of its most d i s h p i s h e d members, and to marly of whom he stood as friend and fellow student, and to the majority as guide and instructor in the fundamental theories and facts of our science, no one item of the chronicle of the life of Lothar Meyer can fail to be of interest. Julius Lothar Meyer was born on the 19th of August, 1830, at Varel ou the Jade, in the Grand Duchy of Oldenburg. His father, Dr. Friedrich August Meyer, was in practice as a medical man in that town ; and his mother, Frau Anna Sophie Wilhelmine, ne’e Biermann, also a native of this same place, was the daughter of a medical man who, during his lifetime, was highly respected and esteemed, and whose memory was cherished in Varel for many years after his death.Lothar Meyer’s mother was an only child, the constant companion of her father, and imbibed from him a love for the pro- fession, which enabled her not only t o enter fully and sympathetically into the labours of her husband, but often-despite her feeble health -to lend assistance in surgical operations. These facts, together with the respected position which their father held, readily explain how Lothar and his brother, Professor Oskar Einil Meyer, should, at the outset of their careers, have decided to follow medicine as their life’s profession.But, fortunately for science, this decision was not carried to its ultimate isaue ; by one brother, medicine was forsaken for chemistry, and by the other for the sister science of physics. Lothar Neyer’s early education was received at a small private school, and from thence he passed t o the recently founded “Burger- schule,” in Varel, at which he remained until his fourteenth year, receiving, meanwhile, private izlstruction in Latin, Greek, and the niodern languages. His rapid growth and consequent delicate health1404 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. necessitated the discontinuance of school work for a time, and his father placed him as a pupil under the chief gardener at the surnrnei- palace of the Grand Duke of Oldenburg, at Rastede.The healthy occupation and the new surroundings soon served to restore the bodily health of the young Lothar, who also gained that lore of nature and taste for gardening which remained a source of enjoyment and recreation to the endof his life. After a year’s sojourn at Rastede, Meyer was sufficiently recovered to be able to resume his studies and to enter the Gymnasium at Oldenburg, at which school he remained until Easter of 1851, when he obtained the “ Zeugnisa der Reife.” I n the summer session of 1851, Lothar Meyer commenced the study of medicine in the University of Zurich, where E’rey was Professor of Anatomy and Ludwig directed the study of Physiology. From Ziirich, in 1833, lie went to Wiirzburg, where the lectures of Virchow on Pathology appear to have been especially attractive to the then student of medicine, who threw his energies completely into the work, industriously visiting the infirmary and actively discharging his duties as a student in the practice of medicine.On the 25th of February, 1854, after a year’s residence in Wurzburg, Lothar Meyer graduated as Doctor of Medicine. Notwithstanding the zeal displayed in the prosecution of his studies, ere the course was completed, doubts arose in the mind of Meger as to the wisdom of his decision to make the practicc of medicine his voca- tion. The attraction expeiienced for the more scientific side of the study gradually asserted itself, and it was only his modest estimate of hia own talents which prevented him arriving at an independent decision.In his doubts as to whether he mere able to advance Roience by his own investigations, Meyer turned to his former teacher, Professor Ludwig, asking for advice on this question. To Meyer’s applicatiou the reply came with no uncertain sound, Ludwig advising Lothar Meyer to put aside all doubts, and to embrace the calling which could alone be congenial t o him. The decision arrived at in the summer 9f 1853, to devote himself to the study of physiological chemistry, was the immediate consequence of the advice of the teacher ; and in the following spring, when his medical studies had been completed and the examination for the Doctor’s Degree had been passed, Lothar SIeyor turned his steps to Heidelberg to study chemistry under Bunsen, and to complete the working out of his dissertation.This letter occupied Meyer’s energies until the autumn of 1856, by which time the investigation on the ‘‘ Gases of the Blood ” was published and forwarded to the Medical Faculty of Wurzburg, by whom it was accepted as inaugural dissertation for the Docto~s’s Degree.BEDSON : LGTHAR MEPER MEMORIAL LECTURE. 1405 The years spent at Heidelberg were times of great moment, and their influence is to be distinctly tyaced in the subsequent work of his life. Many are there in the foremost ranks of the Fellows of this Society who, like Lothap Meger, cherish the fondest recollection of the genial influence of their teacher, Robert Bunsen, whose reputtt- tion for so many years attracted students of chemistry from all parts of the world to Heidelbcrg.Wherein the attraction lay, those of us who have not been so privileged can only guess ; assuredly it was not to be found in a laboratory equipped with all our modern appliances, which do so much to ease the work of a student and so little to develop his resourcefulness ; but rat,her in the results, which cast a halo round the meagre tools with which so many of the all-important discoveries in our science have been made, and make these the desperation of our modern refinements. A description of Gmelin’s laboratory in the cloisters of the old monastery at Heidelberg, in which Meyer worked f o r a year side by side with one of our past Presidents, Sir Henry Roscoe, who has so successfully transplanted much of the Bunsen enthusiasm and methods to this country with inestimable benefit, might serve to rouse feelings of doubt and astonish- ment in the minds of the present day student at the possibility of doing eacient work, where combnstions were made with charcoal as fuel, and other heating operations performed with Berzelius’s spirit lamp ; it may, perhaps, serve to heighten their appreciation of the skill and ability of those who, by the use of such appliances, could obtain resalts of which we have so excellent an example in Lothar Meyer‘s classical investigation of the “ Gases of the Blood.” During Meyer’s Heidelberg “ Studienzeit ” the new laboratory mas opened, with gas and water laid on to all the benches, and the spirit lamp replaced by the Bunsen burner.What these altered conditions of work meant to Meyer and his fellow students i t is difficult for many of us to fully realise.The recollection of the Heidelberg days was ever a source of pleasure and delight to Meyer, who frequently re- ferred to his “ lioch zitrehrter Lehrer,” to whom he dedicated what must be regarded as his magnum opus-Die Nodernew Theorien der Chemie ; nor did Meyer, in recalling the past, forget to remind his hearers of‘ his fellow students, with many of whom he formed life-long friendships. The names of these fellow students include many whose names are honourably associated with the growth and extension of the science of Chemistry during the past 40 years, as the following list attests :- Roscoe, Russell, Atkinson, Baeyer, Beilstein, Barth, Landolt, Lieben, Meidinger, Pebal, Qnincke, and Sehischkow.Nor should it be for- gotten that at this time there worked a t Heidelberg, in the capacity of Privat-Docent, August KekulB, to whom we owe the recognition of the tetravalency of carbon and the theoretical elucidation of the1406 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. constitution of benzene and of the aromatic compounds, theories which have so materially contributed to the advancement of organic chemistry during the past 30 years. During the years spent at Heidelberg, the separation from medi- cine gradually became more pronounced, and the final step drew nearer. Whilst at the University of Heidelberg, Meyer attended Kirchhoff’s lectures, and thus gained an introduction and insight into the mathematical treatment of scientific questions. The decisive blow was struck, the election made, when Lothar Meyer, in company with his friend, Pebal, and in answer t 9 his brother’s entreaty, turned his steps to Konigsberg-there t 3 devote himself to the study of mat hematical physics under the direction of Professor Franz Neu- mann.From that moment, t o quote the words of Professor Oskar Emil Meyer, (‘war die Richtung entschisdert, in d_pr Lothar’s Forscher - geist in Zukunft thatig seiiz sollte, er war fiir die physikalische Chemie gewonnen.” During the year and a half spent at Konigsberg Meyer prosecuted an investigation on the action of carbon monoxide on the blood, tvhicli, in the spring of 1858, was presented to the Fasulty of Philo- sophy in Breslau as dissertation, with the title De Sanguine Onydo Carbonic0 infecto, for which he obtained in July of the same year the degree of Doctor of Philosophy.In the February of the following year, Lothar Meyer established himself as Privat-Docent in Physics and Chemistry in the University of Breslsu, presenting for this pur- pose a brochure on the ‘‘ Chemical Teachings of Berthollet and of Berzelius,” and selecting for his inaugural l e h r e the subject of the ‘‘ so-called Volametric Methods of Chemistry.” A t the outset, Meyer undertook the direction of the chemical laboratory attached to the Physiological Institution, and during his residence in Breslau, delivered several courses of lectures on various branches of chemiHtry applied to physiology, and conducted tutorial classes in both Inorganic and Organic Chemistry. I n Professor Seubert’s account of the life and work of his highly esteemed and honoured teacher, to which, as also t o the writer, I would wish to express my indebkeduess for much of the information embodied in this lecture, there is reprodnced a letter from the Curator of the university, Ober-Prasident von Schleinitz, which shows how completely and unselfishly Meyer threw himself into his new sphere of work ; not contenting himself with unstinted devotion of time and energy, he unsparingly and liberally dispensed much of his worldly goods for the benefit of the Institute.This is all the more worthy of note, seeing that Lothar Meyer himselE WAS not by any means a rich man, and the legacy he inherited from his father, who died a year before Meyer began his university stmudies, had alreadyBEDSON : LOTHAR METER MEMORIAL LECTURE.1407 been materially diminished to supply the “ needf id ” during the L L Lelw- und Wanderjah~en.” In the winter of 1859 one of the Heidelberg group of friends, Beilstein, whose name is a household word amongst chemists, came to Breslau in the capacity of Assistant to Professor Lowig, and in 1864 Lothar Meyer was joined by his brother, Oskar Emil Meyer, who became Professor Extraordinary in Mathematics and Mathematical Physics, to succeed in 1867 to the position of Professor, which he still occupies. It was dnring the residence at Breslau that the Modemen Theorien der Chemie was written, as Meyer himself tells us in his preface to the fourth edition, “ with the desire and hope that its publication might contribute t o the removal of doubts and uncertainties, so frequently expressed at that time, as to the character of the views and theories then contending for supremacy in chemistry.” “ And at the same time to give to others interested in the science an account such as would lead to an understanding of the change through which the system of chemistry had just passed.” The book was written i n 1862, but not published until 1864; it attracted considerable attention at the time, and has materially con- tributed to spread the fame of Lothar Xeyer in all parts of the scientific world. Tw-o years after the publication of this work, Meyer received an inritation to become a teacher in the School of Forestry at Neustadt- Eberswalde, with the understanding that, should circumstances allow, he should receive a Professorship. The invitation was accepted, and in October, 1866, after seven years’ activity in Breslau, Lothar Meyer began the duties of his new position.The post can scarcely be regarded as an ideal one for a specialist, and the descrip- tion given in the invitation cannot he considered as altogether encouraging to one of Meyer’s tendencies, as indicated by his pub- lished works. He was here required to teach the whole of inorganic natural science, more especially mineralogy, chemistry, and physics, nud also to undertake the direction of the study of botany. Before settling at Eberswalde, Meyer married on the 16th August, 1866, Johanna Volkmann, a relative of the famous surgeon, Volk- rnann. Frau Meyer, to whom I am indebted for directing my atten- tion to several important facts in her husband‘s career, still survives, together with their four children. The two years spent at Eberswalde do not appear to have afforded many opportanitics for the development of his ability as an investi- gator, and Meyer cannot long have hesitated as to the manner of the reply he should make to the invitation received in February, 1868, to become the successor of Weltzein at the Carlsruhe Polytechnicum1408 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. the duties of which Professorship he took over in the autumn of illis same year. Shortly after the settlement at Carlsruhe came an invitation to the Professorship at Konigsberg in Prussia, which was declined chiefly on the grounds of geographical position and donbts as to the suit- ability of the clirnate-a decision the more readily made as the Government undertook, in accordance with the wishes expressed, tro provide a residence for the Professor nearer to the Polytechnicum than the one he occupied.The necessity for the change was shown when, in the autumn of 1874, Meyer failed in health to such an extent as to necessitate him relinquishing his duties for the entire winter session, 1874-18 75. The &‘ even teriour ” of the days at Carlsruhe was also interrupted by the outbreak of hostilities between France and Germany, and the Polytechnicurn was transformed into a hospital for the reception of the wounded. Reviving his medical studies, the professor of chem- istry became the active and zealous surgeon.In recognition of these services, Meyer received, at the conclusion of the war, the medal for non-combatants and the ‘( Erinnerungs-Zeichen fur Hulfsthatigkeit im Kriege.” By these rewards for services rendered to his country in its hour of need Meyer, throughout his life, set more than special store. During the residence in Carlsruhe, which extended over some eight years, an attachment to the place had been gradually formed, and the worth of the man had made itself felt throughout the widest circles of its life. Still the call to fill the Chair of Chemistry in the Uni- versity of Tubingen, in succession to Pittig, who had been promoted to Strasburg, was one which could not be resisted, offering as it did a, freer and more congenial field of labour than that afforded by the necessarily more restricted teaching of the Polytechnicurn.Thus, in the spring of 1876, Lothar Meyer became university professor, and for him then began the most productive period of his life. Many investigations commenced in the earlier days and discontinued by reason of unfavourable conditions, were again resumed and brought to a final issue. The name of the Professor served to attract students to the laboratories at Tubingen, and amongEt these vcere to be found representatives of many lands who, in Lothar Meyer, found not only the rimn of learning, the conscientious, painstaking and inspiring teacher, and all that his fame would entitle them to expect, but also one desirous and ready to be their friend. His pupil, and for many years assistant and colleague, Professor Seubert, has given in the Memoir recently published by the German Chemical Society of Berlin, a sketch of the daily life at Tubingen, which shows the high ideal Lothar Meyer had formed of the duties ofBEDSON : LOTHAR MEPER MEMORIAL LECTURE.1409 llis position, and with what marked siiccess that ideal was ivalised. From this portrayal we carry away with us the picture of a man elldowed with gifts and high intellectual powers which entitle his name to a foremost position amongst the names of those who have been contributors to the scientific development of chemistry during the past 40 years. To t.hese were added that modesty and simplicity of character, that love of truth and high smse of honour which secured the respect and appreciation of his colleagues, and inspired the goodwill of his fellow townsmen.The meeting of the British Association in Xenchester in 1887, memorable as i t was in many ways, was more than ordinarily so to chemists. The place oE meeting was John Dalton’s adopted city, the President, Sir Henry E. Roscoe, the founder of the School of Chem- istry there, and to whose zeal and devotion Mancliester is chiefly indebted for the erection of the pile of buildings in which the Asso- ciation was housed, and there-further to enhance the interest-were to be seen Meyer and Mendelkeff genially active i n promoting the work of Section B, under the presidency of one of Liebig’s pupils, Dr. Schunck, whose investigations have greatly added t o our stock of knowledge of alizarin, indigo, chlorophyll, and other vegetable colouring matters.I am reminded of one incident during the meeting which must have left an impression on the minds of all those present ; when, at the conclusion of Dr. Schunck’s address, there was a call f o r a speech from MendelGef, he declined to make an attempt to address the section in English, and simply rose in his place to bow his acknowledgments, an action followed by the rising of DIeyer from his seat next to Mendelkeff, and who, as if to prevent any misconcep- tion, prefaced his speech with the declaration, “ I am not MendelBeff,” a statement which may, perhaps, have disappointed some of his hearers, but the round of applause which greeted his further remark, ‘‘1 am Lothar Meyer,” proved that the feeling, if it existed at all, was more than counterbalanced by the anticipation of the pleasure of listening to the words of one whose name will ever in the annals of our science be justly associated with that of the great Russiaa chemist.The applause which greeted this opening having subsided, Meyer, speaking in faultless English, asked permission to address the section in German, and then proceeded, on behalf of Mendelheff and other foreign chemists present, t o express the pleasure they had derived from listening to the Presidentrial address. For ithe academic year of 1894-95 Meyer had beenelected to be the Rector of the University of Tiibingen, the exercise of the duties of which position had scarcely been relinquished ?hen, on the evening of the 11th oE April OE last year, whilst busily engaged in his garden -a form of recreation in arhich Meyer from the days oE hisresidence1410 BEDSON : LOTBAR MEYER MEXORIAL LECTURE.a t Rastede had continued to delight-he felt the symptoms of an approaching illness. Shortly after entering t’he house he became unconscious, and a t 11 o’clock, six hours from the time of the first attack, Lothar Meyer passed quietly away, surrounded by those endeared to him by the highest of all worldly relationships. And whiIst in the sudden death of Lothar Meyer we mourn the close of the life of a man in the full enjoyment of bodily vigour and of a ripened intellectual activity, whose lovable simplicity of character, whose honesty of purpose, whose breadth of sympathy had endeared him to a wide circle of life-long friends and colleagues, our sorrow is as great at the loss t o science of one whose unremit- ting labours in so many of its branches have enriched it with incal- culable gain.Lothar Meyer’s scientific publications embrace a remarkable variety of subjects and display intellectual attainmerits which find him alike a t home, wbether in the devising of experiments for lecture illustration, the designing of apparatus to supply some want experienced in the laboratory, or needed for the conduct of the in- vestigations of physical constants, or in the extension of chemistry by literary labours and theoretical speculations. As I have already mentioned, Meyer’s first experimental investign- tions belong to the domain of Pbysiological Chemistry, and of these the two most important are Lhose concerned Kith the investigation of the chemistry of the blood.The first paper ‘‘ On the Gases of the Blood,” was published in 1856, in the Zeitsch~ift f i i y Rationelle Medicin, and was undertaken with the object of elucidating the question oE the conditions under which the gases exist in the blood. To solve, in fact, the question, then an open one, as to whether or no the gases are simply absorbed by the blood in quantities subservient to Dalton and Henry’s law, that is, in amounts determined by altera- tions in pressure. The paper, an abstract of which, from the pen of Sir Henry Roscoe, appeared in the Philosophical 2Clagazine of 185i, contains a detailed description of the method and apparatus used, and the results of the analjses of the gases expelled by boiling measured yolumes of blood diluted with water free from air in a vacuous apparatus.The proportion of carbon dioxide existing in a stmate of combination was also determined by acidifying with a few crystals of tartaric acid the blood from which the gases had been pre- viously expelled. The absorption by defibrinated blood of oxygen, carbon dioxide, and nitrogen was also submitted t o a carefully conducted quantita- tive investigation, and with the object of throwing further light upon this all-important subject, the behaviour of solutions of sodium car-BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 14 11 bonate towards caybon dioxide, and to this gas when mixed with others, for example, hydrogen, was examined. * Meyer, by this investigation, placed the chemistry of the gases of the blood iipon a firm experimental basis, proving that the views held at that time were not in accordance, but rather in direct opposi- tion to the facts brought to light by his experiments.Whereas, according to the older doctrines, the gases oxygen and nitrogen were simply absorbed by the blood, and chemical affinity was called in t o explain the manner in which the blood takes up and gives off carbon dioxide, the reverse mould appear to more nearly represent the facts. The greater portion of the oxygen taken up by the blood was proved by Meyer to be in amount independent of the pressure, and to exist in the blood in a state of loose combination with some one of its constituents. The assumption that in the tissues the carbonate of soda in the blood is converted into the bicarbonate, and that this compound gives up some of its carbon dioxide in the lungs, and thus again forms the carbonate, is shown to be essentially improbable.Such a series of chemical changes being entirely unnecessary, as the ab- sorption of the carbon dioxide and the liberation of this gas from the blood, find an all sufficient explanation in the laws regulating the absorption of gases by liquids. Marchand’s observation that no carbon dioxide is produced when oxygen is passed through defibrinated blood which has been pre- viously freed from its absorbed carbon dioxide, is confirmed by one of Meyer’s experiments, thus demonstrating the highly improbable nature of the hypothesis that carbon dioxide is produced by the im- mediate oxidising action of the oxygen in the blood.That the oxygen. existing i n the blood loosely combined with one of the blood constituents can easily pass into other and more stable modes of combination is demonstrated by an experiment made in the course of this investigation. It has already been mentioned that in determining the amount of the gases contained in the blood, the latter, after dilution with water free from air, was boiled and the gases so expelled, collected, measured, and analysed. The proportion of combined carbon dioxide was ascertained by adding crystals of tartaric acid to the diluted blood which had been previously boiled, and the gas liberated by the acid was collected and its volume measured. Meyer observed that if the acid be added before the gases are removed, the bulk of the oxygen is n o t driven off by boiling, a fact abundantly proved by experiments specially made to test the truth of this observation, and shown in the following tabulated results of the analyses of the gases obtained from two samples of blood taken in quick succession,1412 BEDSON : LOTHAR MEYER MEMORIAL LECTURE.(1) after treatment of the diluted blood a t once with tartaric acid, (2) aEter the ordinary method of extraction. Volume of Gases, a t 0” and 760 mm. presswe, obtained f r o m 100 Folztmes of Blood. Oxygen 3-79 18.42 Nitrogen ................ 2.94 4.55 Free carbon dioxide.. ...... - 5.28 Combined carbon dioxide.. . - 20.57 Total carbon dioxide ....... 27.10 26 2.5 I. 11. .................. This observation, demonstrating as it does that the loosely held oxygen readily enters into more stable combination with some con- stituent of the blood, shows clearly also that this oxidising action is not likely to occur in tbe blood vessels themselves, by reason of the alkalinity of the blood itself; but in the tissues, 8ome OC which are known to contain free acid, conditions favouralde to such changes may frequently occur.The conclusions drawn by Meyer from this iuvestigation form the teaching accepted a t the present dar, and are summarised at the close of the paper in the following words :- (( Das B l u t tragt in seiner eigenen Zusammensetzung den Begdator fiir die Aufnahme dieses wesentlichsten Lebensmittels, Ufiabhcingiy con2 wechselnden Drucke des. Atmosphare, zieht das Blu t i.n den Lungen den Sauelatof in ricl~tigen Terhaltnisse an, urn ihn den Organen z u zzcbringen.Nzcr eine Teriindemng des Blutes selbst bedingt eine erhebliche r e yander zcn q d el’ a uf g ei LO 11% i n ene n Quant i t at : jeJe BE u t en tz ie hung w ird daher zu einer XazLel.sto$enfziehung.” This first publication of Lothar Meyer’s, whether it be regarded from the stand-point of the skill displayed in devising means to solve tbe problem in question and in carrying out the experimental work with care and exactitude, o r from the attractire manner in which the results of the investigation are described and the careEul consideration of the conclusions which the results appeay to warrant, is justly entitled to a position amongst the classics of science.Our knowledge concerning the ‘,‘gases of the blood” received further extension by the resulta obtaged in the examination of the action of carbon monoxide on the blood. The results of this enquiry show that this gas is taken up by the blood under conditions similar to these regulating the behaviour of the latter towards oxygen : entering like oxygcn into a loose state of combination with some constituent of the blood, and capable of expelling and replacing volume for rolame the oxygen existing in combination with this substance.BEDSON : LOTHAR METER MEMORIAL LECTURE. 1413 Facts which offer a simple explanation of the poisonous action of carbon monoxide, Preliminary experiments made to discover the nature of the constituent of the blood which exercises this attrac- tion for oxygen and carbon monoxide were, owing to the interruption of the investigation, never brought to a successful issue.Some seveii years after the publication of this paper, Hoppe-Seyler suc- ceeded in isolating this constituent of the blood, which he named Hsmoglobin (Vi~chow’s Awhiu, 1864, 29, 233). Whilst at Breslau, Meyer published an account of a complete examination of the waters from the springs at Landeck, in Prussian Silesia, papers having more than local interest. They contain a description of a method €or estimating the carbch dioxide in natural waters dependent on the removal of the gases by means of a mercurial air-pump, instead of expelling them by boiling, and further attention is directed to the large proportion of nitrogen gas held i n solutiori by the waters from these springs.This last men- tioned fact is more than ordinarily suggestive at the present time in the light of the brilliant discoveries of Lord Rayleigh and Professor Ramsay. It \\-as during this period also that in conjunction with Heiden- hain an investigation was undertaken on the absorption of carbon dioxide by aqueous solutions of neutral sodium phosphate in order to determine the question at issue between Pagenstecher’s statement (1840), afterwards confirmed independently by Marchand (1843 j, and Liebig (1847), and the experimental results of Fernet (1658). Neyer and Heidenhain were successful in ref ding khe conclusions of the last, named investigator and placed the subject in a clear light, explaining the production of the sodium bicarbonate i n this instance as a mass action in terms of the teachings of Berthollet.These investigations belong to the early period of Meyer’s experi- mental work, which, until he became Professor at Carlsruhe, and finally passed to the still more congenial surroundings and duties of a University Professorship at Tubingen, were conducted under not altogether favourable circumstances. Whilst a t Carlsruhe and Tubingen, Mejer’s powers as a11 inves- ti&or are shown in a long series of publications, dealing with ques- tions pertaining to inorganic, organic, and general chemistry. Instead, however, of attempting to discuss the individual com- munications, it will undoubtedly be more worthy of and befitting the occasion upon which we are met if I direct attention to those investigations and speculations which have exercised no unimportant influence in chemistry during the pastl 30 years.Amongst these we have in the first place to consider the part Lothar Meyer took in the development of the great generalisation known VOL. L U X . 3 C1414 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. under the name of the ‘ I Periodic Law,’’ or tohe ‘‘ Natural System of the Chemical Elements.” One of his Jast literarv tasks was the editing for publication in t h e series of Classical Papera, published under the direction of Professor Ostwald, the papers of Dobereinei- and VOU Pettenkofer dealing with the relationships exhibited by the atomic weights of the elements and their physical and chemical properties. In an appendix to these papers, and in the explanatory notes is given an account of the extension which the conception of Dobereiner and von Pettenkofer received at the hands of Dumas, Gladstone, Cooke, Odling, and others. This subject,, some 11 years ago, provided the material for a lecture delivered by Meger at Plochingen (on January 25th, 1885), entitled “ Ueber die rheuere B~~twickelung dpr Atomlehre.” After rerie wing the earlier at tempts to discover relationships between the numerical values employed to represent the atomic weights of the elements, Meyer con- tinues :- “ When at the commencement of 1860 I undertook the preparation of a work which should place before chemists and other men of science the most important of the laws relating to the atoms and their compounds, I soon discovered that by the adoption of the new atomic weights a much greater uniformity existed in the relation- ships between the numbeiw representing the atomic weights, than had hitherto been observed.A t the same time there was shown a regular and continuous change in the vttlency of the elements from family to family, when the families are arranged in the order of the atomic weights of their members. I drew up at that time the following Table ‘I, and also directed attention to the fact that the first differences, with the exception in the case of beryllium the atomic weight of which was still uncertain, were approximately 16, the two following differences approximated to 46, and the last were very nearly double this, namely 87-90.” “ These last two sets of differences are repeated in the groups in the following table 11, in which the first members are wanting.“These groups were also arranged in the order of the atomic weights, with the exception of the last, which, because it consisted of ‘ members of uneven saturating capacities ’ (‘ Stittigicz7gs-capac~tat ’), appeared to me somewhat doubtfnl. At the same time, I did not ove~look the fact that these groups could he arranged t o make one complete table by placing them to the left of those in Table I, and thus placing cadmium before fin, and mercury before lead. The attempt to arrange all the elements in a single table was not succew- ful, inasmuch as certain erroneous atomic weights, namely, Mo = 92, V = 137, and Ta = 137.6, exhibited differences which led me to formulate the two groups contained in Table 111, which groupsTABLE I.Tetravalen t . I Tetravalent. j Tet,ravalent. --- r P Divalent, Difference . . . . . . . . Jifference . . . . , . , . Difference .. .. .. .. Difference . . , . . . . . Difference , . . . . . . . Tetravalent. I - c = 12.0 16.5 Si = 285 89.1 z 44.55 2 8x1 = 44.55 2 Sn = 117% 89'4 = 2 x 4 4 ' 7 Pb = 207.0 Trivalent, - - N = 14.M 16 -96 P = 31'0 44l.O Aa = 75'0 45.6 Sb = 120.6 84'4 = 2 x 43 a 7 Bi = 208.0 Divalen t. - - 0 = 16.00 16 Q7 S = 32.07 46 -7 89 = 70.8 49 '5 Te = 128-3 - - ~~~ TABLE 11. Monovalent . - - F = 19.0 C1 = 35.46 16 '46 G *51 Br = 79.97 46 *8 I = 126.8 - - Monovalent. Li = 7-03 16 -02 Na = 23'05 16 *08 K = 39-13 46 *3 m = 85.4 47 -6 CS = 133.0 71 = 2 x 35.5 (T1 = 204 3) Divalent.W (Be = 9*3?) W (14-7) Mg = 24.0 Ca = U . 0 16.0 5 47-6 5 Sr = 87'6 cn 0 Difference . . . . . . . , Difference . . . . . . . . = 55.1 Ru = 104.3 9L.8 = 2 X M -4 Pt = 197.1 ~~ ~ I Ni = 58.7 45 *6 R11 = 104 0 3 92.8 = 2 x 46.4 Ir = 197.1 Zn = 65.0 46 *9 Cd = 111.9 88.3 = 2 x 44.2 Hg = 200'2 44 '4 g Ag = 107.94 88.13 = 2 x 44.4 cI AU = 196.7 t+ c.r I I I I I cI11416 BEDSON : LOTHAR METER lllEMORIhL LECTURE. Tetravalent. could not in any way consistently be brought into arrangement with the other elementary bodies.” TABLE 111. Hexavalent. --- Ti = 48.0 42 ’0 Zr = 90.0 47 *6 Ta = 13’1.6 Difference ........ Difference ........ MO = 92 42 Vd = 137 47 w = 184 I- --- Such then in brief is Lothar Meyer’s own account of the inception of the classification of the elements, which finds a place in the first edition of the Modernen Theorien. The development of this subject in Meyer’s mind is shown in the sketch of a system of the elements, which, in manuscript form, Lothar Meycr handed, in July, 1868, to his successor in Ebers walde, Dr.Adolf Remelt5 (“ Ostwald’s Classiker der exakten Wissenschaften, No. 68, Ksrl Seubert. Zur Geschichte des Periodischen Systems,” Beit. nnorg. Chem., 9, 334). This table, which is reproduced below (vide Table IV), bears undoubted evidence of having been prepared for a possible new edition of the Modernen Theorien. The mark 9 91, which corre- sponds to the section in the first edition of the Modern Theories dealing with this subject, and the series of references given a t the foot of the table both justify this conclusion.The table contains two elements, namely, chromium and alumi- nium, in addition to those contained in the three tables o€ groups, and in some particulars certain elements have been rearranged ; thus iron displaces nickel, the latter being placed by itself between cobalt and copper, whilst chromium occupies a similarly isolated position and that of aluminium remains doubtful. Meyer himself appears t o have entirely overlooked the existence of this sketch until i t was shown to him by Dr. A. Remelt5 in 1893, on the occasion of his lecture, delivered to the Chemical Society at Berlin. The redetermination of the atomic weights of niobium and tantalum by Maxignac in 1865, and of vanadium by Roscoe in 1867, opened the way for further progress.In a comparatively short paper, dated from Carlsruhe, December, 1869, and contributed to Liebig’s A n d e n (Annalew, VII, Supplement- band 1870, 5, 354-364), Lothar Meyer showed his appreciation of the advantages the new atomic weights offered, and how with these new values some 56 elements including all those elements, saveTABLE TV. 2. 6. 4. --- A1 = 27.3 Go = 58'7 47 -3 Pd = 106.0 93 = 2 x 46.5 0 s = 199.0 7. S. 9. 10. 11. 12. 13. 14. 15. Li = 7.03 16 *02 N& = 83-05 16 '0s I< = 30'13 46 '3 Rb =- 85 *4 47 -6 CS = 133'0 71 = 2 x 35-5 ? TI = 204? Be = 9 . 3 14 '7 I\Ig = 2 4 - 0 16 *o Ca = 40-0 47 -6 Sr = 87'6 49 ' 5 Ba = 137.1 B1 = 27'3 c = 12'0 N = 14.04 16.96 Y = 31'0 44 '0 AS = 75.0 45 -6 Sb = 120.6 87.4 - 2 x 43.7 I, = 208.0 0 = 16'0 16'07 S = 32.07 46 *7 s c = 78.5 49 -5 TC = 125.3 F1 = 19.0 16.46 c1 = 35.46 44 *Ell BY = 79'97 46 *S I = 126'8 16 *;i Si = 28.5 Ti = 48.0 42 '0 Zr = 90.0 47 *G Ta = 13'7.6 110 = 02 45 Vd = 137 47 T T = 154 'DZn = 55.1 49 -2 RU = 104.3 92.8 = 2 x 46 -4 Pt = 197.1 Fe = 56'0 48 '3 Rh = 104'3 92.8 = 2 x 4@4 Ir = 197.1 cu 63.5 44 '4 Zn = 65.0 46 *9 Cd = 111-9 88'3 = 2 x 44.13 Hg = 200.2 - Ag = 107.94 k8 = 2 x 44.4 A U = 196 *7 Sn = 117.6 89.4 = 2 x 4% P b = 207'0 S.I;. Chnelin, Hhd., 5 j Aiitl. i, 47 ff j Miinch. gel. Ann-850, Bd. 30, S. 261 272, abgedr. ; d i t n . Cltem. Pharm., 1838, 105) 187 ; J. DUWAS, C.r., 1837, t. $5, p. 709; auch AILIL. Cheub. Phcc,-)~z., 105, S. 74 u.a.TABLE V. I. -- - Li = 7 '01 ?Be = 9.3 11. -- B = 11.0 C = 11.97 N = 14.01 0 = 15.96 F = 19.1 Na = 22.99 Mg = 23.9 ~ ~______ 111.-- A1 = 27.3 Si = 28'0 P = 80.9 S = 31.98 c1 = 35-38 13 = 34.04 Ca = 39.9 IV. --- - Ti = 48.0 V = 51.2 Cr = 52-4 M n = 54.8 Pe = 55.9 Co = Ni = 58.6 CU = 63.3 Zn = 64.9 V. --- - - AS = 74.9 Se = 78.0 Br = 79.75 Rb = 85.2 Sr = 87.0 ~~~ ~ VI. -- - Zr = 89.7 Nb = 93.7 MO = 95.6 RU = 103.5 Rd = lW.1 Pd = 106'2 Ag = 107.66 Cd = 111.6 VII. -- 'In = 113'4 Sn = 117.8 Sb = 122.1 Te = 128? I = 126.5 CS = 132.7 Ba = 136 *8 VIIT. ---- - - Ta = 182.2 W = 183.5 0 s = 198.6: Ir = 196.7 Pt = 196.7 AU = 196 *2 HE = 199.8 W M U 1x. -- .. Pb = 206'4 e Bi = 207.5 Y1418 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. hydrogen-the atomic weights of which had been determined either by the aid of Avogadro’s law or the law of Dulong and Petit-could, together with the two elements beryllium and indium, be arranged in one table.I n this table, reproduced in Table V, it will be noticed that, as in its predecessor, the members forming the families are arranged in a horizontal series; there are many gaps which, aa Meyer points out, may be at some time occupied by those elements whose atomic weights had not yet been accurately determiued, and possibly by others yet to be discovered. Further, attention is drawn to the fact that the elements in the vertical columns IV, VI, and VIIT exhibit many relationships, e.g., isomorphism in certain of their compounds to the elements in the horizontal series immediately above. For example, titanium is so related to silicon and tin, vanadium with phosphorus and arsenic, chromium with sulphur and selenium, manganese :with chlorine, copper and silver with gold, zinc with magnesium and calcium.It is evident from this state- ment, and also from the table, t h a t Meyer fully appreciated the relationships in the properties of these elements upon which is based the division of the groups of elements into a main and a sub-group as i n the system adopted at the present time, namely, the more com- pletely extended one of Mendel6eff. Of Mendeleeff’s work in the same direction, Lothar Meyer was as fully cognisant as the abstract of the communication of the former, “ Veber die Beziehungen der E’igetaschaften IU den Atomgewichten der Elemente,” which appeared in the Zeitschrift fiir Chentie for 1869, could make him. In fact, Meyer describes his own table as in essence identical with that pub- lished by Mendeleeff, and further prefaces the statement respecting the series of relationships just referred to with the words: “ I will onEy add one remark to those made by Mendelheff in explanation of his table.” But, as it is not my intention to discuss any question of priority, but simply to lay before you an account of the part Lothar Meyer took in the development of this generalisation which has so pro- foundly influenced chemical thought, let us, therefore, return to other matters suggested by this paper “On the Nature of the Chemical Elements as a Function of their Atomic Weights.” The perusal of this work indicates that its author is inclined to regard its evidence of the probable composite nature of the elementary atoms, the existence of these relationships between the properties of the elements and their atomic weights, the interdependence between which he summarises by describing the properties of the elements as periodic functions of the attomic weights.To obtain a complete understanding of the nature of the elementsBEDSON : LOTHAR MEYER NEMORIAL LECTURE. 1419 in their dependence on the magnitude of their atomic weights, it is necesEary to follow step by step the changes of each property as we pass from element to element. The paper now under considera- tion, memorable as it is in so many ways, is especially so, in the example it affords of the first attempt to make such a detailed study Qf these cbangee. Lothar Meyer selccted for this purpose the atomic volumes of the elements, the relation between which and the atomic weights is depicted in a graphic representation, which shows tbe atomic volume to be a periodic function of the atomic weights, with regularly distributed maxima and minima.The curve which repre- sents these changes is dirided by five maxima into six sections, which .exhibit the form of a, series of chains placed in a line. There is 8 strong resemblance betwcen the second and third sections, and between the fourth and fifth sections. In the second and third sections, the atomic weight increases by 16 units in each, whilst iu the fourth and fifth the increase is approximately 46. The curve not only exhibits, as Meyer pointed out, the variation in the atomic volumes of the elements, but also indicates that the fusibility, volatility, malleability, brittlentsp, electro-chemical behaviour, and other physical and chemical properties alter in like manner, conse- quently the properties of an element are determined by its position on this curve.For example, the easily fusible, volatile, and gaseous elements are to be found on the ascending branches of the curve, whereas the infusible elements are found either at the minima or on fhe descending sections. The elements, therefore, whose molecules are easily separated from one another, would experience an increase in their atomic volume in passing by addition to their atomic weight into tho next element. Whereas the infusible and non-volatile elements, were i t possible too convert them into the neighbourirg element, by increasing their atomic weights, would suffer a, dimiuu- tion in their atomic volume.But the utility of this systematic study of the alteratiou in the atomic volume of the elements is not to be found alone in the bean- tiful epit,onie of the periodic law shown by this curve, but also iu the rcvelaticn of errors in the determination of the atomic weights of many elements, and of the indication of the piobable position in the “natural sjstem” of elements such as indium and thallium, so entirely justified by the results of subsequent investigation. In the conclusions set forth in this memoir are to be foulid the natural and independent consequences of the train of thought sug- gested by the cla~sification of the elements given in the first edition of the Jfodernen Theorien, they form a statement and amplification of the law underlying the relation between the properties of the elements and the atomic weights, showing how fully Lothar Metjer had grasped1420 BEDSON : LOTHAR MEYER MEMORIAL LECTURE, its meaning, and the justice of the action of the Fellows of the Royal Society of this country in awarding in 1882 the Davy Medal simul- taneously to Mendel6eff and Meyer, as founders of this great and important generalisation, the “ Periodic Law.” No one has shown his high appreciation of the labours of Mendelkeff in this domain of speculation more than Meyer himself, as a perusal of the Hodernen Themien, will show ; and in the lecture delivered at Plochingen, to which I have already referred, Meyer speaks of Mendelbeff’s brilliant contribution as forming I‘ the coping stone of the building which in the course of years has been erected on the foundation of Diibereiner’s Triads, of a work which did not, like Pallas Athene, spring ready armed from the head of a Jove, but has been gradually completed by the slow, painstaking, and often apparently vain endeavours of a whole series of workers.” The verification and justification of Mendel6eff’s boldly conceived use of this law have undoubtedly contributed to effect a complete change in the attitude of chemists toward speculations of this kind, and have served to awaken an interest in the labours of our fellow countryman, Newlands, the value of whose contributions we should all the rcore willingly recognise when we recall the unsympathetic reception they receired st the time, and the inappreciative remarks they called forth.The little reward obtained by the efforts of those who, prior to 1860, had devoted much time and ingenuity to the study of these relations, finds a ready explanation in the confusion which existed in the minds of chemists as to the meaning of the term “atom,” and the lack of agreement as to the definite representation of atoma. Many of the Fellows of this Society there are who art! able vividly to recall those times, and the tumult engendered by the contending systems ; others, again, less fortunate, perhaps, than they, entirely dependent upon the knowledge acquired from the records of the science, can only by the aid of the imagination attempt to appreciate aright the condition of chemical thought at that time.To many it will be difficult to conceive that almost half a century after Dalton’s atomic theory had been given to the world it should have been necessary for a speaker, at the memorable Conference of Chemists, held a t Carlsrnhe in September, 1860, to emphasise the inadmissibility of using more than one atomic weight for a given element, and to state that one value alone can be accepted as the true atomic weight of an element. Yet such indeed was the case, for, as Meyer himself tells us in the notes appended to Cannizzaro’s famous pamphlet, ‘‘ Di un Corso di l?iloso$a Chemica ” (which in 1891 he edited for Ostwald’s Chtmical Classics), that one of the speeches which greatly coniributedBEDSON : LOTHAR MEYER MEMORIAL LECTURE.142 1 to the advance of the atomic theory was t.hat delivered by Professor Odling, of which this thought was the burden. And whenonce we have realised something of the spirit of those days and the doubts and uncertainbies which must have reigned in the minds of many chemists concerned with the definition of the conception so important to the vitality and growth of our science, we shall the more readily appreciate the sense of peaceful security which the repeated reading of Cannizzaro’s pamphlet produced in Lothar Meyer’s mind. The discovery of the Periodic Law may assuredly be counted as one, perhaps not the least of the benefits which have followed from the explanation given by the great Italian chemist of the apparent contradiction between the law of Avogadro and that of Dulong and Petit. Many of Meyer’s and his pupils’ investigations were undertaken with the object of furthering the systematisation of inorganic chem- istry and placing this portion of the science in a position similar to that which obtains in organic chemistry.In a paper entitled “ Zur Systenzatik der anorgnnischen Chernie,” published in the Berichte of 1873, expression was given to the wish for a change in this direction, and his brother chemisfs were exhorted to undertake a careful and searching examination of the already known compounds of the diiferent elementaiy bodies, and to set on foot systematic investiga- tions of the compounds of the elements of the sevezd groups, and thus provide material for a ‘‘ comparative chemistry.” As a step in the direction of systematisation, Meyer, in this paper, shows how it is possible to deduce the composition of the oxides and hydroxides of the elements by a general formula, in which 2 represents the element, v the valencg deduced from the composition of its highest oxide, a number identical with that repre- senting the group in the natural system to which tlie element belongs for which to prevent confusion, the term .“ index of affinity ” is pro- posed, and n is a small whole number.Applying this to the members of the third series we obtain the following. n = 0 NazO Mgz02 A1203 Si204 P205 S206 C1207 n = 1 H2Na202 - H,Al,O, H2Si205 H2P206 H2S20; H2CI20e &c., &C. I n like manner, formula for compounds of lower stages of oxidation may be deduced by the use of forniula H2nX,0, + - 2, H2,,X20, + - 1, and so on.Amongst the immediate results of this appeal are to be counted the investigations of the chlorides and oxychlorjdes of molybdenum, H2nXaOV + nr V - 1 . V = 2 . V = 3 . V = 4 . V = 5 . V = 6 . V = 7 .1422 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. chromium, and sulphur undertaken by several of Meyer's pupils. TO these may also be added the investigations of Michaelis, which resulted in the discovery of the tetrachloride of sulphur ; the dissociation of the latter and the conditions under which i t is resolved into snlphur dichloride and cblorine afford another example of the influence of temperature on the valency exerted by any given element. In the irrational treatment of inorganic chemistry, as depicted in the majority of chemical handbooks, Meyer found a state of affairs similar to that existing i n organic chemistry, wliich 20 years pre- viously Laurent had so rigorously criticised in his Xe'thode de Chimie. To Xeyer the same causes appeared to be operative in retarding the progress toward the goal, the attainment of which would be the founding of a system of inorganic chemistry which " would not fear comparison with the thoroughly developed system of organic chem- istry." (Moden& Theories, p.170.) Meyer's lecture before the German Chemical Society, delivered in 1893, Ueber den Vortmg der anorganischen C'herizie nach dein Natfiir- Eichen. Systeme der Elernente, should surely contribute to place the " prize " more within our reach, fur in this diecourse he has shown how, by the adoption of certain " artifices " the natural system of the elements may be made the basis of a course of instruction in general inorganic chemistry.Not the least of the advantages of the method. of treatment described in this lecture are those which accrue from the insight afforded into the history of the foundation of modern chemistry, and the gradual manner i n which facts are laid before the student forming materials which serve to exemplify the lams of chemicaal combination Rnd the development from these of the mole- cular atomic theory. The student thus instructed, and having acquired an understanding of atomic weights is prepared for an explanation of the outlines of the natural system. This outline is gradually filled in, not by a description and illustration of the pro- perties of the elements and their compounds, group by group, but first by the facts brought t6 light in the study of the chief types of hydrogen compounds, and the subsequent rsystematic treatment of the elements forming the several groups or families in the " natural sy s tem." It must bo conceded that a student so instructed should form n higher conception of inorganic chemistry than many appear to do, and may possibly be inspired with the desire to devote his energies to add something which may help to make the system more perfect, for so suggestive a treatment could not fail to bring out with due prominence those poifits on which additions to our knowledge are so much to be desired.No account of Meyer's labours in the department of chemistryUEDSON : LOTHAR MEYER MEMORIAL LECTURE.1423 now under consideration would be complete without a reference to the work published by him i n conjunction with Professor Seubert in 1883, in which are given the results of a recalculation oE the atomic weights of the elements. The task was begun by Lothar Meyer himself in Eberswdde in 1867, and, after many years’ interruption, recommenced and completed, as stated above, with the help of Professor Seubert. To some perhaps the task Meyer imposed upon himself may appear an almost thankless one; not so, however, to Bleyer, who saw in the study of the modes of combination of the atoms “ a. new epoch in the history of chemical statics,” and in the study of chemical change the basis of the “ dynamics of the atoms.” To one so minded the reward for the unremitting labour, the time and energy consecrated to the work, would be found in placing upon a certain and sure foundation these fundamental constants, so essential t o tbc advancement of the mechanics of the atoms.The influence of Meyer’s training in mathematics and in mathe- matical physics is evinced both in his experimental work and in his writings, and is shown in the selection of the problems submitted to experimental inquiry, the successful solution of which is to be attri- buted to the happy conjunction of the mathematician with the experimentalist. This is especially true of the series of investigations on the molecular volumes of chemical compounds, which had its starting point in the results obtained by calculation of the molecular volumes of certain gases from Graham’s observations on the rates of ‘‘ transpiration.” From Graham’s results, Professor Oskm E.Meyer deduced the coefficients of friction for the 19 gases experimented on, and by the aid of the relation established by Maxwell between tho rate of transpiration or the coefficient of friction, the molecular weight, tlhe molecular velocity and molecular sectional areas, Lothar Meyer calculated the molecular volumes for these 19 gases. He dis- covered t h a t the volumes so obtained exhibit t~ ratio similar to that exhibited by the molecular volumes deduced for these gases by the aid of Kopp’s law, employing the atomic volumes calculated from liquid compounds; and he established the fact, that the molecular volume of a gas is the sum of the atomic volumes of its constituents.To institute a comparison between the values obtained for the molecular volumes in accordance with Kopp’s rules and those deduced from the coefficients of friction, the latter, which are purely relative values, were expressed in terms of the molecular volume of liquid sulphur diDxide. In 12 cases, the agreement between the two sets of values is satisfactory, as will be seen by an inspection of the following table in which are given the molecular volumes arrived at from the friction constants, and also those calculated from the molecular volumes of liquid compounds. The agreement is more complete1424 BEDSON : LOTHAR MEYER MBM9RIAL LECTURE. when, in the cases of nitrogen and hydrogen and the compounds containing these elements, the atomic volumes obtained from the friction constants are employed, as will be seen by a comparison of the values contained in the third column, in which the molecular volumes are calculrtted with these numbers. It is further worthy of remark that in the case of carbon monoxide and of carbon dioxide a greater concordance is observed between the molecular roluines based upon the friction constants, and the calculated values, when Kopp’s lower value for oxygen is used, that is, for oxygeir combined a8 i t is ill water, instead of the higher value for oxygen as it is assumed to be combined in the “ carbonyl ” group.1IiloleculaT Volicnzes of Gases. From friction. Oxygen .......... Nitric acid ........Carbon dioxide.. .. Hydrogen chloride. Chlorine. ......... Hydrogen sulphide. Methylic chloride. .. Ammonia ......... Sulphur dioxide.. .. Cyanogen ......... Ethylic chloride. ... Methylic ether . . ,. Air .............. Nitrogen ......... Carbon monoxide . . Nitrous oxide.. .... Methane.. ....... Ethylene. ......... Hydrogen ......... 1. 13.8 15.9 26-7 24.1 44.1 43.9 30.0 48.2 23.6 55.1 66.0 53.8 15.0 15.3 15.4 15.7 19.4 33% 6.0 Ctllculated by aid of Kopp’s numbers. 11. IIT. 15-6 15.6 14.5 15.5 31.0 26.6 28.3 25.8 45.6 45.6 42% 42.6 33.6 28.6 50.2 42 8 18% 16.7 56.0 56.0 76.3 59.8 62-8 47.8 - 15-0 4-6 15.3 23.2 18.8 16.8 27-5 33.0 23.0 4 . 0 34.0 11.0 6-0 7 Our interest in these results is due not alone to the fact that they contribute to the advancement of knowledge, but also that they are deductions from some of the valued experimental facts bequeathed to science by one of the founders of this Society and its illustrious first President, Thomas Graham.Lothar Meyer sought next to extend therJe observations on gases by determining experimentally the rates of transpiration of vapours ; the work was commenced in Carlsruhe, and continued in Tubingen,BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1425 the paper containing the results of the first stage of this inquiry being dated from the latter place. Tn the account given in the Armalen der Yhysik und Cheinie (N.F., 1879, 7, 497), the method of observation and the apparatus employed are described. The appa- ratus devised for this purpose is a beautiful example of the same inventive skill which characterises all Meyer's work, and compels our admiration.The rate of transpiration measured is that of the saturated vapour. A long series of experiments were made with benzene, showing (1) that in case of vapours the coefficient of fric- tion increases with a rise in temperature more rapidly than in the case of gases, (2) that the molecular volume of vapours is greater at lower than at higher temperatures, which is also true of gases. The careful and acarching criticism to which Meyer submitted the experimental data revealed the fact tbat the laws governing the transpiration of gases cannot without modification be applied to vapours, and that further information as to the influence of pressure and of temperature on the vapour of benzene is required.Empirically he arrived at an expression for the relation between the rate of transpiration and the pressure of saturated vapours. From the con- stancy of this quantity is deduced a relationship between the co- efficient of friction of benzene vapour, and possibly of all other saturated vapours ; namely, that the coefficient of friction is propor- tional to the square root of the tension of the vapour. In conjunction with 0. Schnmann and subsequently with V. Steudel, the rates of transpiration of a, number of fatty acids and their ethereal salts, and also of several series of homologous com- pounds were determined. The results of these extended observations show that in the majority of cases, homologous compounds have very nearly the same coetlicient of friction.The average values being for = 0*000142 Alcohols, CnHzn + 2O ............ Chlorides, C11E2n + ,Cl ........... 7 = 0*000150 Esters, CILHPll+ .............. = 0*000155 Bromides, C,H,, + ,Br .......... q = 0.000182 Iodides, C,,H,, + ,I .............. 'I = 0*000210 The influence of the nature of the atoms constituting the molecules is shown by a comparison of chlorides, bromides, and iodides of approximately the same molecular weight. The influence exerted by the iodine is found to be greater than that of the bromine, and this again than that of chlorine. The molecular volumes of these various compounds calculated from the friction constants exhibit, a proportionality to those values obtained from their molecular volumes in the liquid state. When the1426 BEDSON : LOTHAR MEYER MEMORIAL LECTURE.first of these value3 is expressed in terms of the moleciilar volume of sulphur dioxide, as was clone i n the case of the g:wes, the molecular volumes are then approxiniatelg half the molecular volumes f o r the 8ame compounds in the liquid condition. That these two sets of values should not’ be identical finds a ready explanation in the fact that the molecular volume of a liquid increases with rise of tem- perature, whereas that of a vapour decreases. Meyer further pointed out that in the case of the isomeric butyl compounds the sectional area of the molecnle of the tertiary isomeride is less than that of the corresponding secondary, and this again than that of the primary compound ; but he found no such regularity in the case of the isomeric propyl compounds.A notable feature in the several publications on this subject, is the nnbiassed freedom with which the experimental results are discussed, and the care which is taken to avoid too hasty “ generaliaation.” The difficulties of the solution of the problem of the influence of the several factors affecting the coefficient of friction of gases and its relation to the form of the molecules ars fully realised and appreciated by Meyer, who is careful to direct attention to many matters which need a searclhg experimental examination before the full and true meaii- ing of these phenomena is realised. The numerous publications of the pnpils of Lothar Meyer, emanat- ing chiefly from the laboratories of Tubingen, are of a, very diversified character. In the selection of subjects for investigation, and in the manner of execution, the influence of the master’s spirit is to be traced.The preparation of compounds, both in inorganic and organic chemistry, has added to the list of compounds already known ; the investigation of their modes of formation and properties has been so directed as to shed a light on points of general interest. The physical constants of many series of compounds have been revised, and our knowledge of the relation between the physical pro- perties and the composition and constitution of compounds received extension. That interesting class of chemical changes usually described rts ‘( contact actions ” has been submitted to careful and critical examina- tion, and our knowledge of “oxygen carriers” and of “chlorine carriers ” and their mode of action very materially advanced. Measurements of the influences of mass, time, dilution, and of other factors in a variety of instances of chemical change, have added many new examples of the truth of the law of Guldberg and W aage.This mere recital of the themes affords evidence of the undoubted attraction which the more theoretical side of chemistry had for Meyer, and at t’he same time show how strong was the desireBEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1427 which animated him to aid in the ordering of the facts of chemistry and thus to contribute to the building up of a system of chemical philosophy. We are also indebted to Meyer for many laboratory appliances, S O R I ~ of which are incidentally mentioned i n the description of the results OP $01118 investigation, others again have formed the subject of special memoirs.The paper on “ Air Baths ” affords ample evidence of his ingenuity in devising apparatus, and also shows that by strict attention to scientific principles grertt efficiency can be combined with economy in fuel. In addition, the exact analysis of gases has been simplified by the apparatus devised by Lothar Mejer and K. Seubert, an account of which formed the subject of a paper con. tributed to the Transactions of this Society. At the same time Meyer drew attention to the advantages in the calculations of the results of gas analysis, which is secured by a stiict adherence to. Avogadro’s law. I n the history of the progress of theoretical chemistry during the past 30 years, the name of Lothar Meger must occupy a foremost position.To the advancement of chemical theory he not only con- tributed as r2 founder of the natural system of the elements, but also as an exponent of the speculations and theories, whether in chemistry or physics, which have combined to awaken an interest in those problems of physical chemistry, the solution of which will bring nearer the redisation of Berthollet’s ideal, a chemical philosophy based on the general laws and principles of mechanics. The first edition of Die Modernen I’heorien was written not alone for chemists, but also to make known to other scientific investigators the nature of the hypotheses and theories forming the basis of chemical philosophy at the time.The time of publication of this work, namely, 1864, was indeed opportune, following as it did immediately on the acceptance by the majority of chemists of the new atomic weights. It marks an epoch in the growth of the atomic theory ; the terms ‘‘ atom ” and ‘‘ molecule ” had at length acquired a distinct, and definite meaning. The publication of a book dealing solely with the theories of chemistry was a matter of great moment in its history, not to be undertaken in a light spirit, nor did Meyer approach the enterprise in any such mood, for only after it had practically been rewritten for a third time was the manuscript handed to the printer. Despite the labour and time expended on this work, the final step was taken with serious doubts as to the value and utility of if, and whether even its usefulness would prove a sufficient excuse for the violation of the accepted traditions of his co-workers in chemistry.These tradi- tions allowed the indulgence in theoretical speculations, when these1428 BEDSON : LOTHAR NEYER MEMORIAL LECTURE. appeared-one might almost say-as addenda to the results of experi- mental inquiry. This attitude of chemists to theoretical speculation suggests that in some occult way they had inherited that contempt for theory which Mephistopheles sought to im.plant in the mind of the pupil of the alchemist Faust. (( Grau, theurer Freund, ist alle Theorie.” This disregard for hypothesis and theory is as little to be justified as is the other extreme. Chemical literature contains many ex- amples of both faults, and certainly many oE the text-books of the science would be better for the infusion of the quickening influence of chemical philosophy into the dry bones which masquerade as a portrayal of the science of chemistry.Lothar Meyer’s book has undoubtedly contributed to effect a change in this direction, and has also led to a more just apprecia- tion and recognition o€ the truths contained in the hypotheses of Avogadro and of Dulong and Petit. At the time when this book appeared, Arogadro’s law was by some regarded as purely arbitrary, the adoption or rejection of this hypothesis was considered of little import ; it received allegiance from others on purely chemical con- siderations. To such the exposition given by Meyer of the applica- tion of these hypotheses in the determination of the atomic weights of the elements, the agreement in the deductions arrived a t by assistance, and the necessity of Avogadro’s hypothesis recognised by Clausius on purely physical grounds, to which Meyer directed atten- tion, must have proved convincing and have serred to elevate these laws to a position of regard higher khan that they had previously en joyed.The feature of the teaching of this work, summarised as we find it in the extended title Die 2l.lodernen Theorien der Chemie und ihre Bedeutung fur die cheniischen Statik is that which gives the distinc- t,ive character to the book. The determination of the atomic weights and the methods used become important, inasmuch as they are concerned with the measurement of the relative masses of the atoms, the invariable quantities, the constants of a theory of the statics of the atoms.The additional property of the elementary atoms, revealed by the consistent use of Avogadro’s law, the specific quality which determines the atom-fixing power of an elementary atom, is studied in the light of an extension of this theory ; and the forrnulm employed to show the constitution of molecules become representa- tions of the equilibrium of the atoms. The discovery of this pro- perty marks a new epoch in the history of chemical statics. To the interpretation of the constitution of solid compounds whose molecular weights cannot be directly ascertained by Avo- gadro’s law, this atom-combining power is extended, but not withoutBEDSON : LOTHAR MEYER NEMORIAL LECTURE.1429 due caution as to the uncertainty surrounding the conclusions drawn. The physical pyoperties of compounds are discussed and interpreted in the light oE the new doctrine of valency, and finally this doctrine is applied to the classification of the elements in the mauner I have already described. With the appearance of the second edition, which was published in 1872, the book altered somewhat in character, the 147 pages of the first edition having grown into 364 ; this addition, in part due to the incorporation of empirical data illustrative of the theories, in part also, to the somewhat lengthy discussion and illustration of the laws of atomic linking, which the development oE organic chemistry and of the benzene derivatives necessitated ; and, finally, to the inclusion of an account of the notable additions made to our knowledge of the “nature of the chemical atoms,” which the speculations of Meyer and of Mendeleeff had revealed.To Meyer himself the second edition had assumed greater import- ance than its predecessor, and he ventured to dedicate i t to his honoured master, Bunsen. The third edition, published five years after the second, is not very materially different from the latter, although it contains an important contribution to the study of the nature of valency, in the recognition ot the fact that the valency of an element may be influenced by the nature of the atoms with which it combines. Thus chlorine, bromine and iodine act as monovalent elements in their compounds with the more electropositive elements, such as hydrogen and the metals ; whereas to oxygen and other electro-negative elements they comport themselves as polyvalent, and, possibly, heptavalent elements.In the fourth edition, which was published six years after the third, and followed by a fifth a year afterwards, the HoderrLen Tlieorien underwent a very material alteration. To the discussion of the problems of chemical statics, which had been treated in former editions, a special part was added concerned with the pheno- mena of chemical change, and the influence of external agents in promoting or retarding chemical action. This third section deals with the “ Dynamics of the Atoms,” thus giving completion to the thought suggested by the earlier editions of the publication of a work which should form an account of ‘‘ Chemical Mechanics.” The translation of the fifth edition of this work by ProfeBsor Williams and myself, which appeared in 1887, found so ready a sale that in three years the edition was exhausted, a fact which surely justifies the belief that the book is so well known amongst chemists as to preclude the necessity of an attempt to sketch in out- line the contents of the third section of the work.The 20 years that have elapsed since the first appearance of Meyer’s Moderneit VOL LXIX. 5 D1430 BEDSON : LOTHAR IfEYER MEMORIAL LECTURE. Thwrien have witnessed great changes in the attitude of chemists towards hypotheses and theories ; a change which in some quarters has led to the institution of a comparison between the modern school of chemists and those of the classical school, not altogether favour- able to the former. Be that as it may, there can be no doubt as to the advantages chemistry has already derived from the acceptance of the kinetic theories of the states of aggregation, of the kinetic theory of electrolysis of Clausius, and of Guldberg and Waage’s theory of the action of mass; the necessity for some such hypotheses was pointed out by Meyer in the first edition of this book in the following passages.“ It will be necessary in the immediate future to introduce some new hypotheses. It sppears that many of the fields of molecular physics which are closely allied to, and are in the almost exclusive possession of chemistry, cannot be successfully cultivated at present without the theoretical speculations and hypotheses advocated by Clausius, which represent the different conditions and forms of matter as determined by the various forms of motion of the corporeal molecules.“ These views, based on the fundamental principles of mechanics -and especially the mechanical theory of heat-alone appear capable of penetrating into the influence which the chemical nature of bodies -the atomic constitution oE their molecules-exerts on the changes of the states of aggregation, e.g., fusion :and solidification, evaporatioii and condensation; on vapour pressure, and on the phenomena of diffusion, absorption, solution, crystallisation, endosmosis, and all similar processes. The theoretical investigation of electrolysis and of the whole field of electro-chemistry can only be successful from this side.In the consideration of all purely chemical reactions, chemical decompositions and chemical combination, such conceptions may become indispensable, in fact very similar ideas have been sug- gested by the consideration of purely chemical phenomena.” The fulfilment of this prediction has not yet been followed by the complete alteration in the old conception of “ aEnity ” as an attractive force, a change also foreshadowed in the early editions of the Nodernen Theorien. The causes which have been operative in retarding this advance in our conception of aEnityare found in the absence of kinetic Speculations on the thermal changes accompanying chemical phenomena. The discussion of the vast accumulation of thermo- chemical data from such a standpoint, as suggested by Meyer, not only in the last edition of the dlodernen Z’heorien, but also in the article published in 1883 in the AnnuZen 011 the “ Basis of Thermo- chemistry,” and, again later, in the contribution to the Zeit.physi- kal. Chem., entitled the “Evolution of the doctrine of Affinity,”BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 143 1 must bring nearer the realisation of a kinetic theory of chemical affinity. Amongst the last undertakings of Meyer’s active life was the pre- paration of a sixth edition of this work, which has played 60 importatit a part in directing attention to the theoretical side of the science of chemistry, and also in arousing an interest in the border- land between chemistry and physics, now cultivated with such zeal and enterprise, and with results so full of promise.Lothar Meyer had repeatedly declined to undertake the task of preparing a new edition of the Moderrt Theories, and when I ap- proached him, in 1890, he suggested that Professor Williams and I should prepare a translation of the smaller book which bad just appeared. In Germany two editions of this book have been published, mid it has also been translated into Russian. When, two years ago, I again wrote to LotharMeyer on the subject of a new edition OF the Modern Theories, he replied that he had declined the invitation of his publishers, feeling that “ it would be tempting fortune to undertake the republication of a work which had been so long before the public.” He expressed himself as “ perfectly content with the influence which it bad exercised in the chemical world,” but felt that a new edition must either be made much shorter or more extensive, and, foreseeing this, he had written the smaller one, namely, The Oz&Gaes of Theoretical Cheniislry .He con- tinues in his letter, “ The world desires at the present time numbers and formulae, and is no longer thoroughly alive to the philosophy set. forth in the Modern Theories.” This decision was, however, overruled, and, on the day of his death, Meyer had completed the manuscript for Book I of the sixth edition, which has since been published, with a preface, by Professor 0. E. Meyer, who has justly described i t as “ an interesting mono- graph on the atoms, of permanent value in itself.” Meyer’s labours were not entirely confined to matters of a purely scientific character.Like many distinguished chemists in this country, he took a great interest in questions relating to education, and contribnted many articles to magazines, $c., on this subject. We are so much accustomed t o look to Germany as the ideal of systematised educatioii, that we are scarcely prepared to see the faults which Lothnr Meyer detected. The difference iu standpoint sufficiently explains the direction of attack. The authorities of the German Universities have, from the first, recognised the equality of all branches of knowledge, and their right to it just recognition in all University education. Further, the rewards and degrees dispensed by them are not to be gained through the single avenue of examination and knowledge of the known, but evidence of 5 ~ 21432 BEDSON : LOTHAR METER MEMORIAL LECTURE.ability to utilise the known and to extend the hounds of know- ledge is demanded from their graduates. How beneficial this attitude has been to the development of the industrial enterprises of Germany is thoroughly understood by chemists. Hence Meyer was not concerned with the problems of technical education as we understand them in this country, but rather with the training of those who were to become students of chemistry in the Universities. For such he advocated a broad and liberal school training in mathematics and languages, and did not wish to see the time and training, which should be devoted to these fundamental subjects, curtailed by instruction in special branches of science carried to such n degree that, when the student comes to the University lecture-room, the subject has lost all its freshness and attractions for him ; and he regards attendance at lectures as a waste of time, and nothing less than eine Arbeit will satisfy him in the laboratory.In England we may surely learn much from such suggestive thought ; let the Universities demand, aa Meyer advo- cated for Germany, evidence of n sound, liberal training before the student matriculates. Once matriculated, permit the undergraduate to pursue some well-defined course of special stildy, and ask a s evidence of the result of such work, not the performance i n an examination hall, but some contribution to chemical knowledge.The industries would then, as in Germany, look to the Universities for the thoroughly traiiied chemists to assist in their direction, aud provide the scientific labour which must form a prominent feature in future chemical industrial enterprise. Learned Societies in Germany, in this country, and in Russia have, like our own, sought to honour themselves by placing the name of Lothar Meyer on the roll of their distinguished members, and, with ns, deplore the loss of one whose thought has left i t s impress on the annals of science, and who has shown by experi- mental work, distinguished alike by the conception, the execution, and the lucid description of resnlte, how best the boundaries of knowledge may be extended. The following list of the published works of Lothar Meyer and of his pupils is taken from Professor Senbert’s account of the life of Meyer (Ber., 1895, 28).I. l.-Die modernen Theories der Chemie und ihre Bedeutung fur die chemische Statik. Breslau. Mmuschke and Berendt. Five editions j 1864, 1872, 1876, 1883, and 1884. a.-Grundziige der theoretischen Chemie. Leipzig. Breitkopf and Hertel, 1890. Second edition, 1893. (Translated into English and French.) (Ti.anslated into English and Russian.)BEDSON : LOTHhR MEYER MEMORIAL LECTURE. 1433 3.-L. M. und Karl Seubert. Die Atoiiigewichte der Elemente aus den Original- zalilen neu berechnet. Leipzig. Breitkopf and Hartel, 1883. 4n. -Abriss eines Lehrganges der theoretischen Chemie, vorgetragen von Prof. S. Cennizzsro. Herausgegeben Ton Lotliar Meyer. Ostwnld’s h’lassiker CJP,.exacfen Wissenschaffen. No. 30. Leipzig. Wilhelm Engelmann, 1891. Abhantl- lungen von J. W. Dobereiner und Max Pettenkofer, nebst einer geschiclit - lichen Uebersicht der Weiterentwickelung der Lehre von den Triaden der Elemente. Edited by Lothw Meyer. Ostzoald’s Klassiker der exncf en 7Vis.Yenschnj’ten. No. 66. Leipzig. Wilhelm Englemann, 1895. 4lr.-Die Anfange des naturlichen Sptemes der chemischen Elemente. 11. Chemical Papers a d Dissertations of his. PwpiIs. 1857. 1858. 1862. 1863. 1864. 1565. 1866. 1867. 1870. 1871. 1872. 5.-Ueher die Gase der Blutes. Inazig. Diss., Wiirzburg, 1857; Hej21p und Pfeufw’s Zeitschr. f. m f . X e d . [N.F.], 8, 256. Abstract, Pogg. Annale,i, 102, 299 ; Phil. Mag., 1857, 14, 263-268. 6.-De sanguine oxydo carbonic0 infecto.Diss. Aug. Vratisl, 1858. Ueber die Einwirkung des Kohlenoxydgases nuf Blut. Henle v n d Pfeufer’s Zeitschr. f. mt. Med. [N.F.], 9, 83 ; Schmidt’s Jahrb.f. d . yes. Med., 101, 22. Pogg. Annalen, 104, 189 ; Liebig’s Annnlen, 110, 312. Ueber die Absorption der Kohlensaure durch Losnngen des neutralen Natronphosphates. Studien des physiol. Insf. zu Breslaic. Heft 2. Leipzig, 1863. Abstract, Liebi-9’s Annnlen, Suppl. 11, 157. Pogg. Annalen, 120, 605. lO.-Bequeme T‘orrichtung ziir Reinigung des Quecksilbers. Zeit. ancri. Il.-Gasometrische Bestimmung der Kohlensiiure in Mineralwassern. 2 p i t . y . 12.-Ueber die Hofmann’sche Reaction auf Tyrosin. Liebig’s Aniznlea, 13.-Chemische Untersuchnng der Thermen zu Landeck in der Grafachn ft 14.-Ueber die Umkelwung der Natriumlinie.Zeit. Chein., 1865, 464. 15.-Ueber die Beziehungen der Specifischen Wiirme zum Atom- uild 16.-Ueber einige Zersetzungen des Chloriithyls. Liebig’s Annalen, 159, 17.-Ueber die Molekularrolumins chemischer Verbindungen. Liebig’s 18.-Die Natur der chemischen Elemente als Function ihrer Atomgewichtr. 19.-Ueber die Apothese Avogadro’s. Ber., 4, 25. Isomorphie von 20.-Apparat zur Regulirung des Luftdruckes der Destillationen. Be?.., 5, 7.-Wirkung des Drucks anf die Verwnndtschaft. 8.--L. M. und Rud. Heidenhain. g.-Krystallform des Desoxylsiiureathplathers. Chem., 2, 241. anal. Chem., 2, 237. 132, 156; Zcifs. onnl. Chem., 3, 199. Glatz. J. pr. C7~em., 1864, 1. Phil. Mag., 30, 390. Molekular-gewicht. Zeit. Chem., 1865, 250. 2s2. Annalen, Suppl. v, 129.Lie6ig’s Antialen, Suppl. VII, 354. Natronsalpeter und Kalkspath. 804. Ref. J.pr. Chena., 1864, 4’76-501. Ber., 4, 53. 1S73. 21.-Bcschreibmg eines Druckregulstors. Liebig’s Annnlen, 165, 303.1434 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1873. 22.-Ueber das Atomgewichte des Molybdins. Liebig’s Annalen, 169, 360. 1875. 24.-Vorlesungsversuch uber Verdampfung oline Schmelzung. Ber., 8, 23.--Bur Systematik der anorganischen Chemie. Ber., 8, 1627. 1627. 25.-osc. Brenken. Ueber Chlorjod. Ber., 8, 487. 26.-Pet. Melikoff. Ueber die Dichte des aus Dreifachchlorjod entstehenden Dampfes. Ber., 8, 490. 1876. 27.-Wasserstoffentwickelung durch Zink und Kupfersulfat. Ber., 9, 512. 18’77. 28.-Ueber Dreifachchlorjod. Ber., 10, 648. 29.-W. Bornemann. Ueber Chlorjod, Bromjod, Chlorbrom und dercn Yerhalten gegen Wasser.Ina.;E/. Diss., Tubingen, 1877. Liebig’s Annalen, 189, 183. 30.-Ueber unvollstiindige Verbrennung. 31.-Emil Elsasser. Ueber eine Elektrolyse mit Wasserstoffentwickelung 32.-otto Schumann. Ueber die Affinitiit des Schwefels und des Saner- Ueber die Einwirkung von Wasserdampf nuf gluhende Ber., 11, 206; ?Vied. dmnlen, Ber., 10, 2117. an beiden Polen. stoffs zu den Metallen. Holzkohlen. Liebig’s Annalen, 192, 288. Ber., 10, 1. Inaug. Diss., Tiibingen, 1877. 1878.-33.-Jolin H. Long. 34.-Ueber Transpiration von Dampfen. 35.-Ueber das Atomgewichte des Berylliums. 3B.-Ludwig Schreiner. CTeber die Siedepunkte der Estei. nnd Aether- Ester des Oxysiiuren. Inaug. Diss., Tubingen, 18’78 ; Liebig’s Annalen, 197, 1. 37.-Georg Pratorius.Ueber die Salze der Chlorcliromdnre. Innug. Diss., Tubingen, 1878 ; Liebig’s Annalen, 201, 1. 38.-Hans Settegast. Beitrage zur quantitatiren Spectralanalyse. Inniig. Diss., Tubingen, 1878 ; Wied. Annalen, [2], 7, 242. 39.-Wilh. Pu ttbach. Ueber Moljbdanacichloride. Inaug. Diss., Tubingen, 1878 ; Liehig’s Annalen, 201, 133. 40.-Friedr. Clausnizer. Ceber einige Schwefeloxychloride. Inaztg. Diss., Tubingen, 1878. 1879, 7, 497. Ber., 11, 576. Der., 11, 2007, 2009, 2011, 2012. 1879. 41 .-Reinigung des Quecksilbers. Bei-., 12, 437. 42.-Jul. Schuncke. Ueber die Losliclikeit des Aethyloxydes in Wassci- und wassriger Salzsiiure. Inaug. Diss., Tubingen, 1879 ; Zeit. physikal. Chein., 14, 331. 43.-James Morrie. Ueber den Einfluss der Mame auf cheniischen Um- setzungen.Inaug. Uiss., Tubingen, 1879 ; Liebig’s Anitden, 213, 253. 44.-J. H. Long. On the diffusion of Liquids. Inaug. Diss., Tubingen, 1879; Wied. Annalen, 9, 613. 4,5.-Emil Elsiisser. Ueber Galvankche Leilung von Metalllegirungen. Wied. Annalen, 8, 455. Ber., 13, 220, 259, 2043. 1880.-46.-Zur Geschichte der periodischen Atoniistik. 47.--Zu Tictor Meyer’s Dampfdichtebestimmung. 48,-Ueber das Atomgewichte des Beryllinms. 49.--Verdampfung ohne Schmelzung. 5O.--Paul Schoop. Ber., 13, 991. Ber., 13, 1780. Ber., 13, 1831. Die Aenderung der Dainpfdicliten bei variablem Druck Inntry. Diss., ‘I‘iibin;eu, 1880 ; Wied. und varjabler Tempemtur. Aitnalen, 12, 550.BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1435 1881. 51.--Verdampfnng ohne Scbniclzung. Ber., 14, 718. 52.-L. M. und Otto Schumann.Ueber Transpiration von Dampfen. Ber., 53.-otto Schumann. Ueber Transpiration von Dampfen. T i e d . Annaleiz, 54.-Eniil Elshser. Ueber die Specifischen Voluniina des Esters der Fett- reihe. &.--l(onr. Bbtsch. Unvollstiindige Verbrennung yon Gasen. Inaug. Dis.~., Tubingen, 1881 ; Liebig’s Annalen, 211, 207. 56.-Alb. Holzer. Ueber einige Phenolather. Inaug. Biss., Tubingen, 1881. 57.-Eug. Sapper. Ueber die Einwirkung der Halogenwasserstoff e auf Znsammengesetzte Aether. Inaug. Diss., Tubingen, 1881 ; Liebig’s Annalen, 211, 1’78. 58.-TLeod. Lehrfeld. Ueber die Einwirkucg von Ainmoniak auf Bibrombernsteinsaure und anf Bibrombernsteinsknreathylester. Inaug. Diss., Tiibingen, 1881. 14, 593. 12, 40. Inau.g. Diss., Tubingen, 1881 ; Liebig’s rlnnalen, 218,302. Ber., 14, 1816.1882. 59.-Ueber die Bildung und Zervetzung des Acetanilids. 60.-L. Gordon Paul. On the identity of certain mixed Ether3 of Oxalic Acid. Inaug. Diss., Tubingen, 1882. 61.--Victor Steudel. Ueber Transpiration yon Dampfen. 1Tnaug. Diss., Tubingen, 1882 ; T i e d . Annalen, 16, 369 ; see also Lolhar Meyer, Ivied. Annalen, 16, 394. 62.-Ernst Noack. LTeber die Phenylester der Phosphorigen Saure. Inaug. Diss., Tiibingen, 1883 ; Liebig’s Annalen, 218, 85. 63.-Georg Kumpf. Ueber Nitrophenyl-Benzyl- und Nitrophenyl-Nitro- benzylather und die Nitrirungsproducte dea Benzylchlorids. Inaug. Biss., Tubingen, 1882 ; Liebig’s dnnalen, 224, 96. Ueber den Austausch von Chlor, Brom, und Jod zwischen organischen und anorganischen Verbindungen. Innug. Diss., Tubingen, 1882 ; Liebig’s Annulen, 225, 146.Ber., 15, 1977. 64.-Rich. Brix. 1883. 65.-Ueber Luftbader. Ber., 16, 1087. 66.-Die Grundlagen der Thermochemie. 67.-Paul Spindler. Der Nitrirungsprocess der Benzolderivate. Inaug. Bi.s.s., Tubingen, 1883 ; Ber., 16, 1252. 68.-Paul Frische. Ueber Nitrite p-Kresyl-Benzyl- Aether. I~Mzu~. Diss., Tiibingen, 1883 ; Liebig’s A m d e n , 224, 137. 69.-Martin Rapp. Ueber die Phenyl- und Kresylester der Phosphoraiiure und ihre Nitrirung. Innug. Diss., Tiibingen, 1883 ; Liebig’s Annalen, 224, 156. 70.-Benj. Kiihnlein. Eine hequeme Darstellung der Psraffine. Com- municated by Lothar Meyer. 7l.-Benj. Kohlein. Ueber die Austausch von Chlor, Brom, und Jod zwischen anorganischen und organischen Halogenverbintlungen. Inaug. Diss., Tubingen, 1883 ; Liebig’s Annalen, 225, 171.Liebig’s Amalen, 218, 1. Ber., 16, 560. 188.1. 72.-Ueber einen empfindlichen Thei*moregulator. Ber., 17, 47’8. 73.-Ueber dethereeter der GlycolePure. 74.-Ueber die Berechnung der Gnsanalysen. ’75.-L. M. und Karl Eeubert. Ber., 17, 669. Liebig’s Annalen, 226, 115. On the calculation of Gas Analysis. Ueber Gasanalysis bei starkvermindertem Diwck. Liebig’s Annalen, 226, 87. Gas andysis under greatly reduced pressure. J. Chem. ROC., 45, 601. J. Chsm. SOC., 45, 581.1436 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. 1884. 76.-Alfr. G. Page. Ueber morganische Chloride als Chlorubertrager. Inaug. Diss., Tubingen, 1884 ; Liebiy’s AnnaZen, 225, 196. ’77.-Ad. Scheufelen. Ueber Eisenverbindungen als Bromubertrigey. Inauy. Diss., Tubingen, 1884 ; Liebig’s AnnaZeti, 225, 196; 231, 152.78.-Aug. F6lsing. Ueber einige Aetherester cler Glycolskure wid Salicpl- siiure. Inaug. Diss., Freiburg, 1 B., 1884. Abstract communicated by Lothar Meyer. Compare also the note, Ber., 17, 669. Ueber die Siedepunktsanoinalien der chlorirten Aceto- nitrile nnd einige ihre Abkommlinge. Inaug. Disz., Tubingen, 1884 ; Liebig’s Annalen, 229, 163. 80.--6. Schlegel. Ueber die Verbrennung yon Kohlenwasserstoffen, ihren Oxyden und Chloriden mit Chlor und Sauerstoff. Liebig’s Annalen, 226, 133. Ber., 17, 484 and 486. 79.-Herm. Bauer. 1885. 81.-Ueber Chlor- und Brom-ubertrkger. Ber., 18, 2C17. 82.-Eisenchlorid nls Jodubertriiger. 83.-L. M. und Karl Seubert. Ueber die Einheit der Atomgewichte. Ber., 18, 1089. On the unit adopted for Atomic Weights.J. Chem. SOC., 47, 426. Das Atomgewicht des Silbers und Prout’s Hypothese. Bet-., 18, 1098. The Atomic Weight of Silver and Prout’s Hypothesis. J. Chew. SOC., 47, 434. Ueber Bromonitrophcnole, Bromonitrqphenetole, nnd deren Amidoderivate. Inaug. Diss., Tiibingen, 1885 ; Ber., 18, 611. Ueber den Austausch von Chlor, Brom, und Jod zwischen organischen u n d anorganischen Halogenverbindungen. Inaug. Diss., Tubingen, 1885 ; Liebig’s Annaleiz, 231, 257. Ueber die Einwirkung vcm Halogenrerhind~uigen des Aluminiuns auf Halogensnbstituirte Kolilenmasserstoffe. Inmy. Diss., fibingen, 1885 ; Liebig’s A?t?2aZen, 231, 285. Untersuchnngen uber den Einfluss der Masse rtuf die Chlorirung brennbarer Gase. Ijzaug. Diss , Tubingen, 1885. Liebig’s Annalen, 233, 1’72.Liebig’s linnnlen, 231, 195. 84.-L. M. und Karl Seubert. 85.-Joh. Lindner. 8G.-Heinr. Spindler. 87.-Conrad Kerez. 88.-Ad. Romer. 1886. 89.-Ueber die Verbyennung ~ o i i Kohlenoxyd. Ber., 19, 1099. 90.-Jul. Giersbach. Ueber die Nitrirung des Banzol. Tnatry. Diss., 91.-Emil Meyer. Ueber die Affinitac der Vitriolmelnlle Zuni Wasser. 1887. 92.-Die bisherige Entwickelung der Affinit8;tslehi.e. Zeit. physikal. Chenz., 93.-Ueber die Einwirkung von Chlorkohlenstoff anf Oxyde. Ber., 20, 94.-Apparat zur fractionirten Destillation Linter verniinderten Drucke. 95.-TyTeber Sauerstoffubertrager. Be?.., 20, 3058. 96.-Ucber die Darstellung von Jodwasserstoff. 97.-Ueber die Constitution des Benzols. 98.-Art,h. Kessler. Tubingen, 1886. Inaug. Diss., Tiibingen, 1886.1, 134; also Phil. Mag., 23, 504. 681. Bw., 20, 1833. Ber., 20, 3381. Liebig’s Annalen, 247. Die Nitrirung des Benzols in ihrer Abhangigkeit von Geki-onte Prei.wrbeif und Inaug. der Masse der wirkenden Stoffe. Diss., Tubingen, 1887.BEDSON : LOTHAR METIER MEMORIAL LECTURE. 1437 1887. 99.- Jul. Eisenlohr. Ueber Nitro- und Bromnitroderivate des Phenols. lOo,--Friedr. Neubeck. Ueber Molekularvolumina aroluatischer Verbin- Inaug. Diss., Tubingen, 1887 ; Zeit. physikal. Chcnz., 1, 101.-Rich. Fink. Vebcr die d5nitiit der Vitriolmetalle zur Schwefelsaure. 102.-Fr. Binnecker. Ueber verschiedene Metallsalze als Sauerstoff uber- I m u g . Diss., Tiibingen, 1887. dungen. 649. Innug. Diss., Freiburg, 1 B., 1888 ; Bet.., 20, 2106. trager an schweflige Siiure. Innug. Diss., Tubingen, 1887.1888. 103.-Ueber die Nitrirung des Benzols. Zeit. physikal. Chem., 2, 676. 104.-Osc. Burcharcl. Ueber die Oxydation des Jodwasserstoffes durch die Sauerstoffsauren der Salzbilder. Inaug. Dis.~., Tubingen, 1888 ; Zeit. physiknl. Chem., 2, 796. Ueber die Verwandtschaft der Schwermetalle zuin Schwefel. Inaug. Diss., Tubingen, 1888 ; Liebig’s Annalen, 249, 326. 106.--Ad. Mente. Ueber einige anorganische Amide. Inaug. Diss., Tubin- gen, 1888 ; Liebig’s Annalen, 247, 232. 107.-Alb. Bonz. Ueber die Bildung von Amid ttus Ester und Ammoniak und die Umkehrung diesel. Reaction. Inaug. Biss., Tiibingen, 1888 ; Zeit. physikal. Chem., 2, 865. 105.-Ernst Schurrnann. 1889. 108.-Ueber Nitrirung. Ber., 22, 18. 109.-Ueber Salpetersaureanhydride. Ber., 22, 23. 110.-Ueber die Umsetzung von Siiureamiden mit Alkoholen.111.-Nachtragliches uber Luftbader. 112.-Ueber Gasheizung. Ber., 22, 883. 113.-L. M. nnd Karl Seubert. 114.-Phil. Liihr. Ber., 22, 24. Ber., 22, 879. Die Einheit der Atomgewichte. Ber., 22, Ueber die Einwirkung von Alkyljodiden auf Cadmium Inaug. Uiss., Tubingen, 1889 ; Liebig’s AnTbah, Ueber die Molekularvolumina einiger Substitutions- Inaug. Diss., Tubingen, Zeit. physikal. Chem., 5, Ueber die Sulfurirung des Chinolins und des Phenols. 1891. 118.-Zur Theorie der Losungen. Sitztingsber. d. K. Preuss. Aknd. d. Wis- 119.-Wm. McKerrow. Zur Kenntniss der Bromubertrager. Inaug. Diss., 120.- W. Pullinger. Ueber Platin-Kohlenoxydverbindungen. Ber., 24, 121.-L. M. und Karl Seubert. Die Einheit der Atomgewichte. Phnrm.Wied. Annalen, 46, 166. TJeber den Umsatz von Wasserstoff mit Chlor und Inaug. Diss., Tubingen, 1892 ; Zeit. physikal. Chem., 9, Ueber die Zersetzung der Aether dutch Wasserstofi- 872 and 1161, 1392. und Magnesium. 241,48. IlL-Sigm. Feitler. . productt! aromatischer Kohlenwasserstoffe. 1889 ; Zeit. physikal. Ckem., 4, 66. 1890. 116.-Ueber das Wesen des osmotischen Drucke~ 23. ll$’.-Heinr. Pnlda. Inaug. Diss., Tubingen, 1890 ; Zeit. physikal. Chem., 6, 190. sensch. zu Berlin, 1891, 48, 993. Tubingen, 1891 ; Ber., 24, 2939. 2291. Rundschau, New York, 1891, 9, No. 4. 1892. 122.-Ueber den sogenaunten osmotischen Bruck. 123.-John A. Harker. Sauerstoff. 673. 124.-Walter Lippert.1438 BEDSON : LOTHAR MEYER MEMORIAL LECTURE. siiuren. 148. 1892 ; Liebig’s Annalen, 276, 129. Inaug. Diss., Tubingen, 1892 ; Zeit. physikat. Chem., 276, 1892. %25.-Herm. Flech. Ueber Magnesium Alkyle. Inaug. Biss , Tubingen, 1893. l26.-Ein kleines Labatoriurnlufttherniometer. 127.-Ueber den Vortrag der anorganischen Chemie nach dem naturlicllen Sptem der Elcmente. Ber., 26,1230. 128.-Ueber die Kiihnlein’sche Darsteilung der Paraffine. 129.--Nachtrag zu der Abhandlung von A. Weigle. 130.-A. Mieigle. Bey., 26, 1047. Ber., 26, 2070. Zeit. physikal. C h e n ~ , 11, 426. Spectrophotometrische Untersuchung der Sdze aroma- tischer Basen. Inaug. Diss., Tubingen, 1896 ; Zeit. physikal. Chem., 11, 227. Ueber die Einwirknng von Chlorwasserstoffsaure auf Aethylalkohol. I w u g . Diss., Tubingen, 1893 ; Zeit. physikal. Chem., 12, 751. 132.-Rich. Theurer. Einwirkung von Salzsiiure auf einige Triphenyl- methan-Farbstoffe. rnaug. Diss., Tubingen, 1893. 131.-John C. Cain. 1894. 133.---Electrolyse der Salzsaure als Vorlesungsversuch. Ber., 27, 2766. Ber., 27, 850. 134.-Ueber Acetylen, eine Warnung. 135.-Ueber die Darstellung der Paraaine. 136.-Die niederen Para5ne. Aethan nnd Propan. Bet.., 27, 2767. 18f.-Ein Trockeiischrankchen &us Aluminium. 138.-L. M. und Karl Seubert. Ueber das Verhiiltniss der Atomgewichte des Wasserstoffs und Sauerstoffs. 139.-Fritz Klunge. Zur Kohlenlein’schen Darstellung der Paraffine. Inaug. Diss., Tiibingen, 1894; Lieb ig’s Annaien, 282, 214. 140.-Ad. Hainlen. Ueber Propan und Aetlian in flussigem Zuetande. Inaug. Diss., Tubingen, 1894; Liebig’s Annalen, 282, 229. 141.-C. Haacke. Spektrophotometrische Untersuchungen uber die Einwirk- ung von Salzsaure auf einige Substitutionsproducte dcs Fuchsins. Inaug. Diss., Tubingen, 1894. 142.-Fritz Woga. Ueber Magnesium-Diphsrigl. Inaug. Diss., Tubingen, 1894. Liebig’s Annalen, 282, 320. Ber., 27, 2766. Ber., 27, 7769. Ber., 27, 2’770. 1895. 143.-Die Constitution der Fuchsine. Ber., 28, 519. 144.-Otto Degner. 145.-Wilh. Ludwig. 146.-E. Manz. Ueber Isobutan, normales Butan, und Propylen in Itnug. Diss., Tubingen, 1895. Ueber gegenseitige Loslickkeit einiger nicht misch- Oekronte Preisarbeit, Tubingen, 1895. Ueber einige Aether des Triphenylmethans und Tritiitro- flussigem Zustande. baren Fliissigkeiten. triphenylmethans. Inaug. Biss. ’ 111. Misce1la’rLeou.s Articles. 147.--Zui* Erinnerung an Leopolcl von Pebal. Nekrolog. Be?., 1887, 20, 148.-Eugen Lellmann. Nekrolog. Ber., 1893, 26, R., 1033. 149.-Die Chemie in ihrer Anwendung auf Forstwirthschaft. Zeit. f. Forst- und Jagdweselz, 1867, 3, 312. 150.-Ueber die neuere Entwickelung der chemischen Atomlehre. Vortrag geldten zu Plochingsn, 25 January, 1885. Boklen’s Nath.- nafww. Mitth., 3, 24 pp. R., 997.COMPOUNDS OF NATURAL YELLOW COLOURIKG MATTERS. 1439 1895. 151.-Ueber den Vortrng der anorganischen Chemie nach dem natiirlichen System der Elemente. Vortrag gehalten in der deut schen chemischerr Geeellschaft zu Berlin, 20 Mai, 1893. 15,”.--Ueber natur~issenscliaftliche Weltanschauurig. Rede am Gebiirtsd feste S. &I. des Konigs geiialteii Tom derzeitigen Rektor L. b L 27 February, 1805. Tiibingen. Ber., 26, 1230. 153.- ‘ I Allotropy.” 154.-Kritiken und Biicheranzeigen. Article for N’ntt’s Dictroiiary, 1885, 1, 128-131. Zeit. f. Chem. Juhrg., 1865-1868, Articles O ~ L Education. 155.-Die Zukunst der deutschex Hochschulen und ilwer Vorbildungaan- stalten. Breslau. Maruschke and Berendt, 18’73. 156.-Akademie oder Unirersitat ? Den deutsclien Forst,- und Land-wirtheu gewidniet. Breslau. Marusclike and Berendt, 1874 157.-Ueber akademische Lernfreiheit. Vortrag in der Dienstags-Gesela schnft zu Tiibingrn, 2.5 Februar, 1879. X o i d uizd Biid, Jahy., 1879, 158.-Uebtr die gewerbliche Schulfrage, Verhandl. d. Centralverb. Dd Industr. Versamml. in Niirnberg, 18 September, 1882. Ber., 8. 98. 159.--Matlematik und Naturwissenschaften in der Einheitsschule. Schriftew de.9 D. Ein~eitaschulcereinb, Heft 1, 1887. 160.--I)ie Reform der hoheren Schulen. 181.-Wunsche fur den niathematischen wid n:! turwissenschafrliclien Unter- rich2 an Gymnasicn. Lrhlig7s Zeilschr. Uas huntanistische Gym- nnsiurn. Jalwg. 1. DaselbPt, Heft 6, 1890. 162.--Die Vorbililung der Sfudirenden. X o , d i t i d Siid, 58, B e f c 172, 57.

ISSN:0368-1645    

DOI:10.1039/CT8966901403

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

COMPOUNDS OF NATURAL YELLOW COLOURIXG MATTERS. 1439 XCI1.-Acid Compounds of Natuml Yellozv Colouring Mcittew. Part IT. BY a. G. PERKIN, F.R.S.E. IN a previous communication (Perkin and Pate, Trans., 1895,67), it was shown that certain yellow colouring matters, when treated with mineral acids in the presence of boiling acetic acid, yield crystalline compounds, the composition of xhich may be generally represented as an additive product of 1 mol. of the colouring matter with 1 mol. of acid ; for inst'ance, the quercetin compounds have the formula, C,,H1,O~,H2SO~, C15H,007,HBr, and Cl,H,oO,,HCl. These substances in the presence of water are decomposed quantitatively into the colouring matter and free acid. I t wqs t4here pointed out that the natural yeZ2ow mordant dye-stuffs, which contain carbon, hydrogeu, and oxygen only, belong as far as their constitution is known principally to three classes, namely, the ketones, xanthones, and phenylated pheno-y-pyrones.Closely allied also to these is the axithraquinone series, which, howeyer, contains no yellow dje-stuff coming under this head.1440 PERKIN : ACID COMPOUNDS co co co co /’\/\/\ A/\A A\/\ /\/\/\ 1 1 1 1 I H I I I I I - \ l l l l \/ \/ yo/\/ \,y-L \A/\/ co Ketone. Xanthone. Plienylated pheno-y-pyrone. Anthraquinone. Of the substances which gave this reaction with acids, quercetin and fisetin were known from the work of Herzig to belong to the third group, whilst it has since been shown that there is little doubt that niorin (Bablich and Perkia, this vol., 792) also belongs to this class.Previously, no member of the second or xanthone group could be obtained for examination, and but one member of the ketones was available, and it was, therefore, pointed out that before attempting to assign a constitution for these compounds with acids, it was ad- visable to study the behaviour of members of all these groups in this respect. With this object, the investigation has been continued from time to time, the isolation or purification of many of the substances employed being necessarily slow. Though some of the results are of a negative character, not only are they interesting theoretically, but they tend to show that the property of reacting with acids is peculiar t o and distinguishes the quercetin group from those other classes of yellow mordant dye-stuffs at present known.Ketone Group-Of this class, “ alizarin yellow A ” (trihydroxybenzo- phenone), ~ 6 ~ , * c o o ~ 6 ~ , ( o H ) , [(OH), = 1 : 2 : 31, and “ alizarin yellow c ” (gallacetophenone), C,H,(OH),*CO*CH,, were cxamined, but no compounds with an acid could be obtained from them. I n the previous paper (Zoc. c i t . ) , i t was shown that maclurin (pentahydroxp- benzophenone) does not combine with acids, and as these three sub- stances may be considered as typical dye-stuffs of this group, it appears evident that the ketone coloixring matters do not yield acid compounds. It is of interest to mention here that catechin from Catechu, kino‘in from Malabar Kiiio, and cyanomaclurin from Artocarpus integrifolia, also do not yield these compounds with acids.The constitution of these substances is not known, but in some respects their properties are similar to those of the ketone group. Xanthone Group.-T hose selected for examination were gentisin, the colouring matter of gentian root (Kostanecki and Tambor, Monatsh., 1895, 15, 1) ; datiscetin obtained from the glucoside datiscin which exists in Datisca cannabina (Schunck and Marchlewski, AnnuZen., 1894, 277, 261), and euxanthone. The constitution of these is given in the former paper. As a result it was found that they yielded no compounds with mineral acids. Various members of the Awthi-aquinone group also gave nega- tive results. The compound of purpuroxanthin with acetic acidOF NATURAL YELLOW COLOURING MATTERS. 1441 :3CI4H8O~,2CzH4O2, (Plath, Ber., 1877, 10, 615), is interesting, but this is rather a case of acetic acid of crystallisation, than of an acid coinpound such as those described in this paper.A somewhat similar product is that from rhamnrtzin (Trans., 1895, 67, 498), C17M1407,C2H102, which I obtained in a similar way by crystallising this substance from acetic acid. Quercetin Grozy.-The colours of this class previously examined were quercetin, rhamnetin, rhamnazin, fisetin, and morin. Since ihen, however, the acid compounds of luteolin (this vol., 208), and rnyricetin (ibid., l287), have been described, and at the same time i t was shown that these colouring matters bear a close relationship t o qnercetin and fisetin. The various compounds of these colouring niatters with acids which have been obtained are given in the follow- ing table.Myricetin, Cl,Bl~Os Qaercetin, CI5Hl0O1 Rliamnetin, C,6H&j Rlismnazin, Cl,H,,Oi Morin, CI,HloOi Luteol in, C1,H1006 Fisetiii, C15H,006 I Those marked with an asterisk have not previously been analysed, ilnd this R as due to the fact that with few exceptions these substances when heated to 100' are decomposed with evolution of acid. As previously shown (Zoc. cit.), this difficulty was avoided in the case of a hydrochloric acid compound (morin hydrochloride) by using a special method of analysis, aud it now appeared desirable to examine, if' possible, another of these unstable componnds in a similar way. Quercetin hydrochZoride, freshly prepared, was strongly pressed in order to remove as much adhering acetic acid as possible, suspended in water, and after standing 12 hours, the regenerated quercetin was collected ; it weighed 0.5552 gram ; the chlorine in the filtrate corresponding to 10.72 per cent. ClJ€1007,HC1 requires C1= 10.48 per cent.Attempts were now made to analyse the hydriodic acid compound of quercetin, b u t with such unsatisfactory results that this was abandoned. This compound is rapidly decomposed on exposure to the air, evolving hydriodic acid even at 40", and is probably very slowly attacked even when washed with acetic acid. Mo&z Hydriodide.-The hydrobromic and hydrochloric acid com- pounds of this colouring matter resemble those of quercetin, but the sulphuric acid compound cliff ers from those of the other colouring1442 PERKIN : ACID COMPOUNDS matters of this group in that during its formation 1 mol.of water is eliminated ; thus its formula is C15H806,H2S01, and not Cl5HlOO,,H2SO4, AS one would be lead to expect. It was interesting, therefore, to examine its bydriodic acid compound, and here again n further dis- tinction between the behaviour of niorin and quercetin was observed, -the cornpound being perfectly stable a t 100". 0.1243 dried a t 100' gave 0,1915 CO, and 0.0295 H,O. C = 42-01 ; H = 2.63. C,,H,,O,,HI requires C = 41-86 ; H = 2.55 per cent. Liiteolin Hydriodide.-In contradistiction to the principal haloid acid compoonds of the colouring matters shown in the above table, those of luteoliri have been previously found (Zoc. cit.) to be exceed- ingly stable, undergoing no alteration even a t the temperature of boiling aniline, and appearing to crystallise with 1H20.It appeared probable, therefore, that its hydriodic acid compound would also be stable, and this was found to be the case. 0.1273 gave 0.2043 CO, and 0.0292 K,O. C = 43.59 ; H = 2.53. 0.1125 ,, 0.1790 CO, ,, 0.0285 H,O. C = 43.39 ; H = 2.79. This compound contains, therefore, no water of crystallisation, and differs in this respect from the hydrobromic and hydrochloric acid compounds. Friedlander and Riidt (Bey., 1896, 29, 878) have lately obtained ct colouring matter which they consider to be the first artificid nieniber of the quercetin series, dihydroxyflavone, CI5Hl0O6,H1 requires C = 43.48. H = 2.65 per cent. by the interaction of chlorogallacetophenone with benzaldehydc i l l the presence of alkali.Discussing the constitution of this dihydroxy- flavone i n a second paper (&id., 1753), they state that like the iiatural colouring mattem it yields with mineral acids beautifully crystalline salts readily decomposed by water ; it, therefore, behaves in this respect like the members of the quercetin group above studied.* The only rernaining member of this class which had not * Kesselkaul and Kostanecki in a later paper (Bey., 1896, 29, 1886) consider that the reaction proceeds in a different manner, the colouring matter being in realit,y not dihydroxyflavone but a benzylideneanhydroglycogallol, c,H~(oH)~<~;>o:cHc~H~. To this Friedlaander and Riidt have not yet replied.OF NATURAL YELLOW COLOURING MATTERS. 1443 yet been examined was chrgsin, the colouring matter of poplar buds, to which the following constitution has been assigned 0 Some of this was prepared according to Piccard's method ( B e y ., 1873, 6, 884) but curiously enough was found to be iizcapable of combining with acids in this way. I n concluding these experiments, it appeared of interest to examine the behaviour toward acids of some substitution products of these colouring matters, and for this purpose quercetin tetramethyl ether, dibromoquercetin, an& tetrabromomorin were selected. The former yields with sulphuric acid, although with dificulty, an exceedingly unstable compound, c r p tallising in orange-red needles, b u t is not acted 011 by hgdrobromic or hydrochloric acid. Its be- haviour is, therefore, identical with that of rhainnetin (quercctin monomethyl ether), described in the previous paper (Zoc.cit.). From di bromoquercetin and fetrabromomorin, acid compounds could not be obtaiiied. In the previous paper (Zoc. cit.), it; Ras stated that these acid coni- pounds on treatment wikh boiling acetic anhydride are decomposed apparently with production of the acetyl compound of the colouriiig matter. To be sure of this, quercetin enlphate was digested with boiling acetic anhydride without the addition of sodium acetate. The substance was quickly attacked, a colourless solution being almost im- mediately formed ; after heating for one hour, this was poured into water, and allowed to stand several days. As the acetylised product separated from the mixture with difficulty, a, little alcohol was added and this greatly facilitated its deposition.The colourless precipitate was collected, and after crystallisation from alcohol, formed colourless needles, melting at 189-191°, and having the properties of acetyl- quercetin. Theoretics 1 Consid era t i o m The results of this investigation show that members of the ketone and anthraquinone group do not yield cornpounds with mineral acids, and that all members of the xztnthone class here examined are also devoid of this property. On the other hand, all members of the quercetin or phenylated pheno-y-pyrone group, with the exception of chrysin, combine with acids, and, further, whereas the methyl ethers of quercetin react only with sulphuric acid, the bromine substitution products of quercetin and morin yield no compounds of this class.1444 PERKIN : ACID COMPOUNDS This property of combining with acids is possessed, as previously described, by hsemate'in and brazilein (Eoc.c i t . ) ; from resacetejin also, Nencki and Sieber ( J . pr. Chem., [2J, 23, 54) have obtained the corn- pounds Cl6Hl,O4,HCl + 2H20 and (CI~H&~)Z,&SO~, but as the true constitution of the substances themselves is yet unknown, they possess at present but little interest. More interesting are the acid compounds of the phthale'ins, of which fluorescein (Baeyer, Annalen, 18'76, 183, 1) yields a sulphate, CzoH1205 + H2SO4 = CzuH,20,sOa + H2Q9 and orcinphthdein (E. Fischer, AnnaEelz, 1876, 183, 63) a hydro- chloride, C22H,sOa,HCl. In a paper on the constitution of fluorescein, Nietzki and Schroter (Bey., 1895, 28,50) describe a hydrochloric acid compound of colourless fluorescein diethyl ether, (I) which salt crjs- tallises in intensely yellow needles, readily decomposed by water.To this they assign the constitution (111, based on the theory that whereas in the free state fluorescein possesses a lactone group, that in the form of its salts and other coloured compounds it has il quinonoid structure, 0 \/ /'roo= A close resemblance in fact can be traced between these compounds and the salts of the triphenylmethane and allied bases. In considering quercetin group, the constitution of the acid compounds of theOF NATURAL YELLOW COLOURING MATTERS. 1445 i t appears to me that their formation may be represented in two ways: (1) either similarly to these phthalein compounds, or (2) by the saturatioii of the ethylene bond in the pyrone ring.Thus, taking fisetin hydrochloride as an example, its constitution mould then be 0 OH 0 OH Fisetin (stable moclification) . Unstable mcidificntion (not known), 0 H OH Hydrochloride. Hydrochloride. In favour of this first formula is the intense orange to orange- red colour of these acid salts, compared with the pale yellow colour of the original substances.* Further, it is possible in this way to account for the non-production OE acid salts from the substituted bromine derivatives. The quercetin compound studied by Herzig was fo:iiid to be peculiar, in that by frequent recrystallisation it was slowly decomposed, and that by reducing agents it could be recon- verted into quercetin. This is no doubt due to the fact that tho bro- mine substitution takes place in the phloroglucinol nucleus, for, as is well known, tribromophIoroglucino1 possesse,s somewhat similar properties.It is very probable that, on bromination, the hydroxyls adjacent to the bromine i n dibromoquercetin assume the ketonic con- dition, the formula in this case being unsusceptible of change under the influence of acids, Moreover, by this formula (I) the decomposition of these acid com- pounds by acetic anhydride can be understood, in that the acetyl compounds of these colonring matters exist only in the stable, colourless, or non-quinonoyd form. The acid compounds of fluoresce’in and orcinphthalein (Zoc, cit.) are, however, more stable thau those of the quercetin group, for the former is not altered by washing with cold water and crystalli- sation from alcohol, and both require hot water i;o effect their decom- * Armstrong, “ Theory of Coloured Carbon Compounds ” (Proc.Chem. Soc.). VOL. LXIX. 5 E1446 COMPOUNDS OF NATURAL YELLOW COLOURINC MATTERS. position. In general properties, however, they appear to be very similar, and the above distinction appears easy to understand when the difference in constitution of these two groups of colouring matters is considered. Fo~rnzcla ZI.---The difficulty with which the ethers of quercetin react with sulphuric acid, and tlieir non-reaction with the halond acids, distinguishes more markedly this class of colouring matter fi-om that of the phthale'in group, in so far as the latter has been examined in this respect.Fluorescein diethyl ether (Zoc. cit.), for instance, readily combines with hydrochloric acid. Taking the con- stitution at present assigned to luteolin, quei cetiii, and rhamnetin as correct, the effect on the stability of the halo'id acid compounds pro- duced by the substitution of the hydrogen in the a-position in the pyrone ring by hydroxyl or niethoxyl is remarkable. 0 OH Luteolin. Quercetin. 0 OH Rhamnetin. For instance (1) all haloid acid cornpoutids of luteolin are stable when heated to 180°, moreover, the hydrochloride and hydrobromide appear to crystallise with lHzO. (2) Quercetin hydrobrotnide is stable at looo, but, when heated to this temperature, the hydrochloride and hydriodide are decomposed with evolution of acid.(3) Rhamnetin does not combine with the haloTd acids. On this account the second constitution above given for these acid compounds suggested itself, namely, that which depends on the satu- ration of the ethylene bond in the pyrone .ring. Experiments carried out in this way on the behaviour of chelidonic and meconic acids, . co COOHAOH COOH,, I II ' 0 towards mineral acids added no support to this theory, for no addi- tive products were t h u s obtained. It is also not'eworthy that neit'herSELL STUDIES ON CITRAZINIC: ACID. 1447 these acids nor the members of the quercetin group form additive compounds with bromine. The strong colour of t'he acid salts of the quercetin group appears so cogent an argument in favour of the quinono'id formula, that of the two it must bc considered by far the mom preferable. I am actively engaged in the study of natural yellow dye-stuffs, with the hope of isolating new members of this class. If such be obtained, the study of their behaviour with mineral acids should throw further light on the nature of this interesting reaction. From the above experiments it appears probable that the colour- ing matters of the xantlione class do not react with acids; but this cannot be absolutely decided until other members of varied constitu- tion are available for examination. Should this be the case, how- ever, this property of forming compounds with acids will be of value in that it can be employed as a means of distinguishing the members of the quercetin group from those other natural classes of ?:on-nitrogenoti,s, yellow, mordant d y e - s h p which are at present known to exist. Clothacorkem' Besearch Laboratory, Yodishire College. Djeing Department,

ISSN:0368-1645    

DOI:10.1039/CT8966901439

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

SELL : STUDIES ON CITRAZINIC: ACID. 1447 XCIII. --Studies on Citmziwic: acid. Part IV. By WILLIAM JAMES SELL, M.A., F.I.C. Idroduct ion. MANY years since, it was shown by Tiemann and Reimer (Bey., 1876, 9, 423, 824) that by the interaction of sodium hjdroxide and chloro- form with phenol a mixture ot' the sodium derivatives of salicyl and paroxybeuzoic aldehydes was produced. Later, Tiemann and Lewy (Be?.., 1877, 10, 2216) applied the same reaction to dihydroxy- benzene derivatives, notably to resorcinol, fi-om which they obtained both a monaldehyde and a dialdehyde. This method, as is well known, has since been recognised as a general one for introducing the aldehyde group into the liydroxyl derivatives of benzenoid hydrocarbons. Up t o the present time, however, no attempt seems to have been made to apply this reaction to derivatives of pyridine, although these compounds have many interesting relationships with benzene derivatives.The pyridine derivative chosen for the application of this inter- action was citrazinic acid, a substance to which the following con- stitutional formula (I) was assigned by Hofmann and Behrmann (Ber., 1884, 17, 2681), but which, as aliown in this series of papers1448 SELL: STUDIES ON ClTRAZINlC ACID. (Trans., 1893, 1035; 1894, 28, 828) behaves in many respecte as having the tautomeric one (11). SOOH YOOH C C \N.. \/ N Assuming for our present purpose that citrazinic acid has the symmetrical constitution assigned to it by Hofmann and Behrmann, i t will be noticed that each of the hydrogen atoms is in the ortho- position with regard to the hydroxyl group on the same side of the ring, and para to that on the opposite side.If, therefore, the same rule of displacement, applies to pyridine derivatives as is observed in those of benzene, we should expect only one derivative containing a, single a,ldehycle group t o be possible, although of course there is not only the possibility, but the probability, of the introduction of two aldehyde groups into the molecule. These compounds would be represented by the formula YOOH C COOH /\ 11. OHC+' g*CHO . HO*C C*OH "/ Working on the lines indicated above, the following compounds, (1) The disodium salt of the monaldehyde, formed to the extent of (2) The monaldehyde acid. (3) The oxime of the monaldehyde acid. (4) The phenylhydrazine salt of the hydrazone.amongst others, have been isolated and analysed. more than 60 per cent. of the citrazinic acid taken. EXPERIMENTAL. so dim^ Salt of the Monalclehyde. Following the directions given by Tiemann and Lewy (Bey., 1877, 10, 2216) in their research on resorcinol, that, to diminish the pro- portion of bye-products a less amount of the hydroxy-compaund should be taken than is the case with phenol, the following p ~ o - portmioils of the materials were found to work well in practice, no citritzinic acid being left unacted on. 25 grams of citrazinic acid,SELL: STUDIES ON CITRAZINIC ACID. 1449 200 of soda, and 125 of chloroform were mixed i n a cnpacisus flask connected with a reflux condenser, and heated by a small flame for about six hours, the termination of the action being shown by the colour which from the first is of a deep reddish-purple, gradually fading to a yellowish-brown.The filtered liquid on Lcing saturated with carbon dioxide gave a, copious precipitate of crystalline matter which, after draining by the aid of the pump and recrystallisation, consisted of the disodium salt of the monnldehyde. This crptallises from warm water in cream-coloured, nodular masses composed of opa,que needles containing 2H20. If, however, the solution, saturated at the ordinary temperature, be cooled down, the crystals deposited are large, faintly coloured, transparent prisms with 5H20. As a rule, however, the solution, after concentration, remains in a condition of supersaturation, and, on baing induced to crystallise at the tempera- ture of the laboratory (about 15O), deposit,s chiefly the form with 2H20, mixed, however, with a small percentage of the other form.A typical specimen of the substance deposited under these conditions gave the following numbers on analysis. 0.175 lost at, 182' 0.027 H20. 0.3595 gave 0.1865 Na,SO,. Na = 16-80. 0.231 ,) 0.121 ,> Na = 16.96. 0.2125 ,, 9.71 C.C. moist nitrogen at 15' and 783 mm. N = 5.32. C,H3N06Na2,2H20 requires N = 5.32 ; Na = 17-49 ; H,O = 13.68 p.c. The transparent, faintly yellow crystals, which are somewhat efflorescent in dry air, gave the following numbers on analysis. 0.473 lost 0.132 at 180". H20 = 27.90. 0.324 gave 0.1465 Na2S04. Na = 14.62. 0.727 ,, 0.320 ,, Na = 14.25. 0.251 ,, 9.7 C.C. moist nitrogenat 16' and 758.8 xnm.N = 4-49. C,HsN05Na2,5H20 requires N = 4-51 ; Na = 14.51 ; H,O = 28.39 P.C. H20 = 13.42. 0.1875 ,, 8.71 C.C. ,, ,, 19' ,, 785 ,, N=5*51. 0-2155 ,, 8-45 C.C. 3 9 ,, 757 ,, N = 4.54. The Monaldehyde acrid. When an aqueous solution of the sodium salt is mixed with excess of hydrochloric acid in the cold, B precipitate is produced consisting of spherical groups of needles which, after washing and drying, are faintly yellowish ; it is slightly soluble in cold, more readily in hot water, as also in alcohol, ether, and acetone. If, however, heat is applied in effecting solution, the liquid becomes coloured, and the recrystallised product is invariably so ; this i s owing to the occurrence of a certain amount of decomposition with formation of a purple-red 5 3 2I450 SELL: STUDIES ON CITRAZINIC ACID.substance, the nature of which is at present under investigation. On the application of heat, the crystals lose their water of crystallisation at about 130-140°, and at higher temperatures become purple-red, and finally blacken without melting. The substance does not restore the colour to a solution of magenta decolorised by sulphurous acid (Schiff's reaction), and does not reduce Fehling's solution. The silver salt may be precipitated from a solution of the normal sodium salt and dried at 100" without change, but if the solution be first rendered alkaline by sodium hydroxide, metallic silver is formed on heating. The precipitated aldehyde gave the following results on analysis. The numbers refer to the undried substance, unless otherwise stated. I.0.5504 lost 0.0489 a t 127'. HzO = 8.88. 11. 0.490 ,, 0.390 ,, HZO = 8.86. 111. 0.2310 gave 0.3885 CO, at 0.057 H20. C = 45.86; H = 2-74. IV. 0.202 ,, 13.12 C.C. nitrogen at 15' and 770 mm. N = 7.70. V. 0.3435 ,, 21% C.C. ,, 16.5"and 759 mm. N = 7-30, Determinations I11 and IV were made on the dried substance, V on the undried substance. C7H5N06 requires C = 45.90; H = 2.73; N = 7.65; whilst C7H,N0,,2Hz0 requires N = 6-96, H,O = 8.95 per cent. The Oxime. A specimen of the pure sodium salt, weighing 2 grams, was dis- solved in water, mixed with rather more than the calculated quantity for 1 mol. of hydroxylamine hydrochloride and a slight excess of sodium carbonate, and, after a few hours, the mixture was strongly acidified with acetic acid ; a copious, pale yellow precipitate, eonaist- ing of fine needles, was thus obtained which, after washing with water and drying in air, formed specimen (1).Another specimen was prepared from 5 grams of sodium salt, using two molecular proportions of the hydroxy lamine salt with the calcu- lated amount of sodium carbonate, allowing the mixture t o stand over night, and precipitating by a slight excess of dilute hydrochloric acid. This is sample (2). A third specimen (3) was prepared exactly as in (2), except that only one molecular proportion of hydr- oxylamine salt was employed. The determination I was made with specimen ( l ) , I1 and I11 with (2), and IV with (3). I. 0.3037 lost 0,0252 at 97". H2O = 8.29. 11. 0.2275 ,, 0.0187 in a vacuum.H,O = 8.26. 111. 0.21 gave 23-2 C.C. nitrogen at 15' and 770 mm. N = 13.11. IT. 0.16 ,, 17.75 C.C. nitrogen at 15' and 770 mm. N = 13.16. Calculated for oxime with 3 mol. of water, N = 12.96 ; H20 = 8.33 p.c.ACTION OF ACIDIC OXIDES ON SALTS OF HYDROXY-ACIDS. 1451 Yhenylhyd~azi?te Salt of the Hydrazone. The effect of phenylhydrazine acetate on a solution of this alde- hyde acid is not t o give the simple hydrazone, but, as would be expected, its very stable phenylhydrazine salt ; to prepare this, the aqueous solution of the sodium salt is acidified with acetic acid and mixed with a solution of phenylhydrazine acetate, when the solution immediately becomes semi-solid from the deposition of this salt in long, yellow needles. These were collected, and, after washing with hot water, in which they are but very slightly soluble, recrystallised from methylated spirit.The crystals, dried in a vacuum, gave the following results on analysis. The samples analysed were from two different specimens of the sodium salt, No. 1 from one specimen, and the others from a different one. 0,1392 gave 22.6 C.C. nitrogen at 18' and 755.0 mm. N = 18-62, 0.1135 ,, 17.75 ,, 17" ,, 766.4 mm. N = 18.28. 0.1195 ,, 18-75 ,, 18' ,, 766.4 mm. N = 18.22. CIgH,,N,04 requires N = 18.37 per cent. Before concluding, it may be remarked that one of the most interesting of the subsidiary products of this reaction, of which only a partial study has as yet been made, is a very stable and sparingly soluble acid which is formed to the extent of about 5 per cent,of the citrazinic acid taken. Analysis indicates its empirical formula to be C4H3NO2, but a study of its salts and nitro-derivative renders it certain that some multiple of this would more correctly represent its moiecu- lar formula. I n conclusion I have much pleasure in expressing my thanks to Mr. T. E. Tadman, B.A., Scholar of Queen's College, for his assistance in the analytical work recorded in this paper. Univemity Laboratory, Cambridge.

ISSN:0368-1645    

DOI:10.1039/CT8966901447

出版商:RSC    

年代:1896

数据来源: RSC