摘要:

1280 L XXV. -Act ion of Fo rrnalde k yde on Phen yllz. y di mine aizd 011 some Hydi-azolzes. By JAMES WALLACE WALKER, M.A., Ph.D. IN the preceding communication I have described a compound formed by the interaction of formaldehyde and phenylhpdrazine, differing both in properties and in composition from that obtained from these substances by Wellington aud Tollens (Bey., 1885, 18, 3300). After an extended investigation into the cause of this difference, it was found, as will be ehown in this paper, that the nature of the compound produced by the interaction depends on the relative con- centrations of the two reagents, as well as on other external con- d i ti ons. Preparatioit of the two Isomeric Substances, C LJHIGNI. One of these has been already described by Wellington and Tollens (Eoc.cit.), and is obtained as a crystalline precipitate when SL large excess of formaldehyde is allowed to act on phenylhydrazine. When recrystallised froni a mixture of alcohol and toluene, i t forms rhombic tablets, melting at 183-184O. If, however, the two substances be allowed to act on each other in hydrochloric acid solution, even in presence of a large excess of formaldehyde, the substance melting at 183-184O is not the only one produced. To a solution of 10.4 grams of formaldehyde in 500 C.C. of water, containing also 3 grams of con- centrated hyd~ochloric acid, a solution of 5 grams of phenyl hydrszine hydrochloride was added. The substances are in the proportion of 10 mols. of formaldehyde to 1 of phenplhydrazine. There was an immediate white precipitate, which afterwards changed to R hard nodule.It was shaken with alcohol, to remove water from it, and then three times extracted with boiling ether. From each extract a crop of crystals was obtained on evaporation, the first melting at 123-160°, the second at about 120°, and the third at 109-115'. The residue undissolved by the ether was recrystallived from ethylic acetate, in which i t was readily soluble; it then had thc melting point 180--182O, and was therefore the substance discovered by Wellington and Tollens. The three crops of ciytals from ether were united and dissolved in a small quantity of benzene, and some alcohol, i n which they seemed much less soluble, was added ; this caused no precipitation, but on evaporation in a desiccator, a small quantity of prismatic crystals separated, melting at 111-115°.This substance is the chief product when the phenylhydrazine hydrochloride is in large excess.ACTION OF FORMALDEHYDE ON PHENYLHYDRAZIWE 1281 Sixty grams of phenylhydrazine hydrochloride were dissolved in 4 lityes of water, and 7 grams of a 40 per cent. solution of form- aldehyde added. The substances are in the ratio of 4.5 mols. to 1. ?'he precipitate formed slowly, and, after three days, a crystalline cake was separated and dried ; i t weighed 7 grams, and its melting p i n t lay between 109-115". It was recrystallised from methylic alcohol, in which it seemed less soluble than in ether, 1.8 gram requiring 25 grams of the boiling alcohol to dissolve it, and yielding on cooling 1-5 gram in large, slightly yellow prisms, melting at 111-113°.The melting point did not change on recrystallisation. The substance was found to cont'ain C = 71-35 ; H = 6.44 ; N = 22.33. CI5H,,N4 require3 C = 71.43 ; H = 6.35 ; N = 22.22 per cent. The new substance has therefore the same composition as the foi-merlg known compound derived from phenylhydrazine and form- ddchyde. That they are isomeric, and not polymeric with each other was S ~ O W I A by a deterniination of their molecular weights by the boiling point method. The molecular weight of the substance melting a t 183-184O was found to be 277 in toluene solution, that of the substance melting a t 111-113" to be 275 in benzene, instead of the calculated 252. The two are therefore isomeric wit,h each other, but the natureof the isomerism has not yet been determined, the few experiments which have been made for this purpose having yielded no results.When heated with glacial acetic acid both me destroyed, dark brown resins being produced ; both behave in the same way when dry hydrogen chloride is passed into their ethereal solutions ; and phenylhydrazine and formaldehyde are both without furtber action on them. No compound with either could be obtained by beating with methylic iodide for half an hom on the water bath. h'either of them appeared to be reduced by dissolving sodium i n its alcoholic solution, as almost the whole of the compound of higher melting point crystsllised from the alcoholate solution, and fio ammonia or inethylic amine was given off from that melting a t 111-113'.The formula proposed by Wellington and Tollens for the first of since it contains no t Iicse substances, namely, doubly linked nitrogen, does not allow of stereoisomerism, so that so:ne such structure as V V must be adopted for the other. From a recent note on the preparation of the latter, C. Goldschmidt (Ber., 1896, 29, 1361) appears to have been unable at times t o obtain it, but by using the above proportions I have nerer failed to obtain a t least the yield quoted. CsH,*r*CH2*r*C6H, CH,:N NICH,' C6Hj*N*N*CHZ*N*N*CsH5 CHZ CH, VOL. LXIX. 4 Q1282 WALKER : ACTION OF FORMALDEHYDE Foyma Ed ehyd c and Bxcess of PIm Ly 1 hy d ratiuc. As already stated under the electrolysis OE sodium glycollate, a compound of formaldehyde with phenylhydraxine was obtained, whose composition corresponded to the simple formuIa C,H,N,.I t has been very often prepared in the course of this investigation froni commercial formaldehyde by adding 2 rnols. of phenylhydrazine in acetic acid solution to 1 niol. of the aldehyde, but the precipitate thus obtained was found t o be very variable in melting point, differ- ent preparations having different melting points, lying bet,ween 160° and 180'. The precipitate is faintly yellcw, and crystallises from benzene or ethylic acetate in pearly leaflets, which, however, h v e not a sharp melting point, and cannot be purified by further recrystal- lisation, owing probably to the sparing solubility of the subst'ance in all solvents. For example, 5 grams of one preparation melting n t 163-168', whose composition was found by analysis to correspond to the formula C7H8NP, was six times recrystallised from boiling benzene, with the following result.Crystallipation 1. 2. 3. 4. 5. 6. 'Ie1ting 146-155'. 155-159' 149-155'. 148-153". 140-145'. 149-151". Its composition was found to have remained unchanged, and its mole- cular weight determined i n ethylic acetate was found to be 127 ; C7H8N, = 120. This substance would seem to be therefore, for the most part, the brue hydrazone of formaldehyde. Like the two former compounds, it gives a t once a brown resin when hydrogen chloride is passed into its solution in ether o r ethylic acetate. The strange raria- tion in its melting point was found t o be due to the fact that it readily polymerises to a substance of much higher melting point and of double its molecular weight.point } Pyeparation of the Poly in eric Substance, ( C:H8Nz),. By dissolving the substance melting a t 146-155' in a little hot aniline, and precipitating it at once by pouring into a layge quantity of alcohol, crystals were obtained, similar in appearance to the original, but melting a t 189-193'. AnalTsis pointed to the same formula, C,H,N,, but tl determination of the molecular weight in toluene gave a much higher value, namely, 210 instead of 120. This substance also could not be obtained with a sharp melting point by recrystallisation, but a method of obtaining it in a state of purity was finally discovered, through an attempt made to reduce the com- pound C7H8N, by adding sodium to its alcoholic solution.2 grams of substance, melting at 158-165", were heated to boiling with 100 grams of alcohol, and, although a11 was not dissolved, 16 gramsON PHENYLHYURAZINE AND ON SONE HPDRAZONES. 1283 of sodium were rapidly added. The solid which remained after washing with alcohol weighed 0.8 gram, and melted a t 210- 212". 0.5 gram of it, when dissolved in 100 C.C. of boiling alcohol, yielded on cooling 0.5 gram, melting a t 210-211*5°. It was also in the form of very small leaflets. This experiment suggested the method adopted for obtaining the polymeride pure. 12 grams, melting a t 145-170', were heated for half an hour on the water bath, with 100 grams of sodium alcoholate containing 9 grams of sodium. The solid, when collected, weighed 11 grams, and melted at 205-209'.When dissolved in hot aniline and poured into alcohol, it gave a crystalline precipitate, in very fine leaflets, which weighed 9.4 grams, and melted a t 210-212'. Analysis of this substance, performed at first in an open tube, gave unaccountable results, for example, C = 68.89, 69-09, 69.09 ; H = 6.76, 6.59, 6.66. (Ci€18Nz)2 requires C = 70.00; H = 6.67; N = 23.33 per cent. Those done later in a closed combustion tube gave values in agree- ment with tlhe formula. C = 69.59, 69.74 ; H = 6.89, 6.77 ; N = 23.2.5 per cent. The molecular weight of the substance was determined in toluene. The constant E for toluene is calculated in the ordinary way from the equation E = 0.0'tT2jZ, where E is the heat of evaporation of 1 gram, and T the absolute boiling point.For toluene, T = 383*S', and I = 83.55, therefore E = 3526. It had been already observed that by long-continued boiling the substance decomposes, crystals of a lower melting point being deposited on cooling, which are most probably a mixture of the polymeric with the simple form, This was confirmed by the molecular weight determination. After each addition of fresh substance to the boiling toluene, the temperature rose rapidly for four c'r five minutes, and then slowly for 20 minutes, after which it remained constant for 10 minutes. The quick riae of temperature for each fresh quantity of substance, calculated sepa- rately, gives a value for the molecular weight approximating to the formnla (C,H,N,), = 240; whilst the reading after the temperature had become constant, gives a value midway between CiH,N2 and (C,HsNz)2.See Table, p. 1284. On cooling the solution, crystals separated in leaflets melting a t 155-157". Most probably, therefoile, the simple hydrazone has never been prepared free from an admixture of its polymeride. I n one case, a sample was obtained which gave, on analysis, C = 69.72 ; H = 6.61 ; N = 23.25, and melted much lower than any other pre- paration, namely, at 126*5-128*5°. The pol ymeride, (C7H8Nz),, melts sharply a t 210-211~5', even when heated very slowly, turne 4 Q 21284 WALKER : ACTION OF FORMALDEHYDE Substance. slightly yellow, solidifies on cooling, and melts again at 200--20jo. It decomposes with slight evolution of gas when heated to 240O. Toluene. Quick rise. Entire rise. 0 -220' 0 *086 0.108 0 -268' 0 '420 0.549 Molecular weight calculated from 0.16'70 0 *2437 0.3494 ~ ~~ 12 -565 7 1 I ? g!: 1 175 163 275 l f 9 I n order to determine the relation in which these substances stand to the two isomers already described, in which all the hydrogens attached to nitrogen are replaced by CH, groups, they were treated with excess of formaldehyde in the expectation that one or both of the more complicated compounds, C,JH,,N4, might be found.The result wits negative, but the Sam* new substance was obtaitied from both. Action of Formaldehyde on Met heneh y dyazone. When either the simple substance C7HBN2, or its polymeride, (C7H,N2)2, is kept a few days, or is heated on the water bath for a few minutes with a large excess of formaldehyde, it is changed almost quantitatively into a new compound which is soluble in ether, and crystallises out of the solution in large, transparent prisms melt- ing at 139-140O.It is, therefore, neither the substance prepared by Wellington and Tollens melting at 183-18$", nor its isomer melting at 111--113O. Analyses showed that it has the formula C,aH16N40. It was found to contain C,,H,,N,O requires C = 68.09 ; El = 6.38 ; N = 19.86 ; 0 = 5.67 p. c. Its molecular weight, in toluene solution was foiind to be 292, C,sH,8N,0 = 282. The substance melts a t 139-140°, is readily soluble in benzene, toluene, and ethylic acetate, less so in alcohol and ether, from all of which it crystallises in large, colonrless prisms. It remains quite unchanged on exposure to air. Like all the other compounds of phenylhydrazine with formaldehyde, its ethereal solu- tion is immediately deconiposed by dry hydrogen chloride, a brown resin being produced.It remains unchanged when its alcoholir: solu- tion is acted on by sodium, the entire amount being recoverable from t,he solution. An attempt was made to remove the oxygen atom by dissolving the substance in hot phenylhydrazine, but it crystalliaed C = 67.99 ; H = 6.40; N = 20.25.ON PHENTLHYDRAZISE ASD ON SOME HYDRAZONES. 1285 out unalt,ered on cooling. The oxygen atom is, therefore, no longer present in the carbonyl condition. Assuming that the substance frorn which it is formed, C:HSN2, has the constilution of an ordinary liycir,zzone, the only way of representing the formation of this new coinpound is by supposing that 3 mols. of water are eliminated from two of hydrazone and two of formaldehyde hydrate thus BCH2(OH)?+SC,H,*NH*NCH, = 3HzO + C,H,*r'CH,*O*CHz*8*CBH,, CH?:N N:C H,* C.Goldschmidt (loc. cit.) has prepared a substance having the saxe composition as th? above, but finds for it the zueltiag point 125' instead of 139-140'. It is somewhat remarkable that, once the simple hydrnzorie is formed, the further action of formaldehyde should lead to the pro- duction of a substance entirely different from that directly formed from plien~lhydrnzine in the presence of excesq of foimaldehyde. This fact would seem to indicate t k t somehow the union between the CH, and the C6B,.NzH groups is diffei-ent in CGH,-N2H:CHz and i n (CGH,Nz),(CH,),, and that, when the radicles have once taken up the position peculiar to the first of these, the production of t,he second is no longer possible, that only the oxygsn compound can then be formed.If so, one would expect to obtain always the same class o€ cornpound by the action of formaldehyde on other hydrazones, in which the combination is kuown to be of the form C,H5*NH*NR. To test, this, the hydrazones of benzaldehyde and acetophenone were employed. Action of Fornzaldeh yde on Benzylidenehy drazone. The substances were allowed to remain for a long time together a t the ordinary temperature, and the solid, after being dried on a porous tile, was washed with ether to free i t from some benzaldehyde. I t melted a t 115-125", but., after being twice reciytallised from ether, i t melted at 134-135'.Analyses showed that it contained GO oxygen. C = 79.70; H = 6.11 ; N = 13.98. Cz7H,,N, requires C = 80.20 ; H = 5.94 ; N = 13.86 per cent. CzeHz,N,O requires C = 77-43 ; H = 5.99 ; X = 12-90 ; 0 = 3.69 p. c. A determination of the molecuiar weight in toluene gave the values 448 and 424, C2,HzrN4 = 404. The only possible constitution for this compound is, therefore, QH* . I t crystallises in large, transparent, colourless prisms, which, unlike all the previously C6H5*T*N:C H* C6H5 CsH5*N*N:CH*CaHJj1286 ACTION OF FORMALDEHYDE ON PHENYLHTDRAZISE. described substances,, is not entirely decomposed by acids, but, on heating it with strong hydrochloric acid, the solution gives off benz- aldehyde. Action of Formaldehyde 012 Aceto~he?zone7Ly!7?.azo?ze.The substances were allowed to stand as in the last experiment, but the crnde product formed was much more smeary from the separation of acetophenone. After washing with ether, the residual solid was fractionally crystallised from ethylic metlate, by which means it was separated into two portions, one melting a t 1 8 5 O , the other a t 139-140'. The latter, from its crystalline appearance arid melting point, was eviden tly the oxygenated compound of mettiene- hydrazone. The substance melting a t 155" crystallises also in large, colourless prisms, which are fairly soluble in ethylic acetate, benzene, and toluene, less so in alcohol and ether. 0 1 1 boiling with strong hydrochloric acid solution, it gives off a strong odour of acctophe- none. The values found for its moleciilar weight in toluene were 396, 402, 410, (C,,H,,N,O = 372), and arinlyses showed that it had the above composition.C,,H,,N,O requires C = 74-19 ; H = 6.4.5 ; N = 15.05 ; 0 = 4.30 p. c. This compound, therefore, unlike that from benzylidenehydrmone, contains oxygen, and is formed from a molecule OE methenehydrazone and one of acetopheuonehydrazone by the action of 2 mols. of form- aldehyde. C = 74.22; H = 6.6.5 ; N = 15-06. I t s constitution may be represented as C~H,*~.CH,*O*CH~*~* CsH5 XCH, N: C (C H3) C&' Since hydrazones, whose structure is knomu to be normal, yield both classes of compounds, there is no reason to assume that methene- hydrazone has a different coiistitu tion from hydrazones in general. This is further borne out by the observation that formaldehyde can displace benzaldebyde and acetophenone, producing in the latter case at least the same oxygenated compciund as is formed from methene- hydrazone.But, on the other hand, unless different, forms of combi- nation be assumed, there is no explanation, first, of the existence of two substances having the composition (CsH,N2),(CH2),, avd, secondly, why one or both of these should not be formed from CcH5*N2H :CH,. I n one preparatioii of the simple hydrazone, when the ethylic acetate from which the crude precipitate had been recrystallised was evaporated to a small volume, some crystals separated in broad tables which melted sharply a t 210-21 I" with immediate decom-COLOURIXG PRISCIPLE OF THE BARK OF NYRICX XAGI. 1287 position. It dissolved easily in ethylic acetate and toluene, and its molecular weight in the latter solvent W R S found to be 250; this ya!ue points to the same formula as that of the polymeric modifica.tion of methenchydrazone, namely, (C7H,N,)? = 240. It differs, however, from the latter in solubility, in that it decomposes on melting, and does not decompose on long boiling in toluene solution, but crystallises unchanged when the solution is evaporated. The entire amount was only 0 4 gram. I t was found to contain C = 69.76; H = 5-93. CI,H,,NI requires C: = 70.00; H = 6.67; N = 2.3.33 per cent. The value found for hydrogen was too low, but unfortunately there was noc exough substance to wpeat the analysis. Besides these numerous crystalline compounds of fornialdehydr! wit.h phenylhydrazine, the two reagents were found to give a clear oil, both in alkaline solution with excess of the aldehyde, and in neutral solution with excess of phenylhydrazine ; this substance has, however, not yet been investigated. The foregoing investigations mere carried o u t a t the suggestion and under the direction of Professor Wislicenus in his laboratory a t Leipsic, and I take this opportunity of expressing to him my thanks for the continued help and advice which he has given me during the progress of the research.

ISSN:0368-1645    

DOI:10.1039/CT8966901280

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

COLOURIXG PRISCIPLE OF THE BARK OF NYRICX XAGI. 1287 LXXV I,-The Colouri.rzg Principle contained in the By Amavn GEORGE PEEKIX and JOHN JAJIES HummL. Bark of Myrica iiagi. Part I* IN the course of examining the tinctorial properties of some Indian dye-stuffs (J. SOC. CAe7n. I?2d., 1895) our attention was especially attracted by the behariour of the bark of Myricn nagi. Not only did the colouring power compare favourably with that of such well- known dye-stuffs as old fustic and quercitron bark, but in some respects it seemed to differ from all other yellow mordant dye-stuffs. Having subsequently received a larger supply through the kindness of the authorities of the Imperial Institute, London, the chemical examination of this dye-stuff was undertaken, and the results are recorded below.Nyrica ?iagi, also called JI. sapidn, JI. Integrifolia, ill. rubra, &c., belougiug to the MyricaceE, is the box-myrtle or yanqnm of China. It i,r ail evergreen dioecious tree possessing an aroniatic odour, and is met with in the snbtrcpical Himalayas from the Ravi eastwards, also1288 PERKIS ,4SD HUMMEL : THE COLOURING PRIKCIPLE in the Khasia Rlountains, Sylhet, and southwards to Singapore, and distributed to the &lalay Islands, China, and Japan. The bark is said t o have been exported from bhe North-West Provinces, Rumaou, &r., to other parts of India i n recent years to the extent of about 50 tons per annum. I n Bombay, i t is met with under the name of kaiphaZ, and is there worth 1-2 rupees per maund of 41 lbs., being entirely imported from Northern India.According to MY. 7V. Cold- stream it is used i n Sirmur (Sinzla district) for dyeing pinlr, and also as a, tanning agent for fancy leather work arid for. medicinal p u r p o s es . The bark has an astringent taste, and in the powdered condition acts as an irritant on the mucous membrane of the nostrils, indeed it is said to be used occasionslly as a snuff iii catarrh with headache (Dictiunar!y of the Econoinic Products of Iiidia, G. Watt, Vol. V, p. 303). So far as we are able to learn, the chemicd examisation of this bark is here made for the first time. E x P E R I M E N T A L PA RT. The ground bark (1,000 grams) was digested for six hours with 10 times its weight of boiling water, the mixtore strained through calico, and the residue treated again in a similar manuer.Experiment showed that by extracting the filtrate with ether a small nmount of culouring matter could be thus obtained ; the ethereal extract sepa- ra'ted, however, with difficulty from the aqueous liquid, and as also a very large quantity of ether was necessary for this process, the following method appeared preferable. To the combined boiling aqueous extracts, a solution of 60 grams of lead acetate was added, when a bulky, yellowish precipitate was obtained, whicb, on pro- longed boiling, became dirty white ; t h i s consisted almost entirely of the Iead compound of tannin matter, and contained but a trace of colouring matter. This was removed by filtration, wasbed with water, and the filtrate treated with more lead acetate solution until a precipitate was no longer formed ; the lemon-yellow lead compound was then collected, washed, and decomposed while still moist by means of boiling dilute sulphuric acid.The brown liquid, which now contained the colonring matter, was removed from the lead sulphate by decantation, and extracted twice with ether ; the yellow crystal- line residue left on evaporating the ethereal extract was dissolved in a little alcohol, and the solution diluted with boiling water. The crystals which separated on cooling, were collected, and extracted two or three times with small quantities of boiiing acetic acid in order to remove a colourless wax-like substance which was present in some quantity. By recrystallisation from dilute alcohol, the pro-COYTAXXED IS THE BARK OF JITRICA NAGI. 1289 duct was obtained in a pure condition.from 100 grams of bark averaged from 0.23 t o 0.27 gram. 0.1139, dried a t 160", gave 0.2380 CO, and 0*0350 H,O. 0.1199, dried at 160', gave 0.2480 CO, and 0.0385 H,O. The yield of colouring matter C = 56.97 ; C = 56.46 ; H = 3.41. H = 3.57. C,,H,,Oa requires C = 56.50 ; H = 3.24 per cent. It formed a mass of light yellow, glistening needles closeIy resern- bling quercetin in appearance, and melting above 300" with deconi- position. When heated between watch glasses, the mass became carbonised, and a small quantity of yellow vapour was evolved, which, on cooling, condensed t o minute needles of the unchanged substance. It is very sparingly soluble in Imiling water, somewhat, readily in alcohol, and almost insoluble i n chloroform and acetic acid.Though closely resembling in appearance the colouring matters of the qnercetin group, it is readily distinguished from those a t present known by the colour changes it produces when dissolved in alkalinv solutions. Wit11 dilute potassium hydroxide, a green solntion is first, formed ; this, on exposure to air, rapidly assumes a deep blue tint, which in its t u r n gradually becomes dull red-violet. With strong alkali a fairly permanent orange-coloured liquid is obtained which, when diluted, passes through the colour changes recorded above. A soiution of ammonia produced somewhat similar results, the colours obtained having, however, a redder tint. The addition of lead acetate to its alcoholi,: solution throws down a reddish-orange precipitate which becomes 3-ellower on boiling.The colouring matter dissolves in cold sulpkuric acid, forming a deep red solution, which deposits the unchaiiged substance on adding water. Its aIcoholic solution is coloured brownish-black by ferric chloride. In examining the dyeing properties of this new colouring matter, for which we propose the name nzyricetiw, experiments were carried out with it side by eide with equal weights of pure preparations of quercetin, fhetin, moriu, gentisin, and euxanthone, using woollen cloth mordanted with chromium, aluminium, and tin. It was a t once apparent that ;t strong resemblance existed between the shades given by myricetin, quercetin, and fisetin, in fact, so similar were thsy, that unless placed side by side one might easily be mistaken €or the other.Thew differences are best seen in the table, p. 1290. This table shows that, so far as its djeing properties are concerned, rnoriu belongs to a distinct group, and the same may be said regard- i n g gentisin and euxanthone. By examination in Ziesel's apparatus, myricetin wits foucd to con- tain no methosy-groups.12'30 PERKIN AND HURLMEL : THE COLOURISG PRINCIPLE Alum i n i ui . Myricetin . . , . Fisetin ...... Quercetin .... Gentisin ...... ........ { 2 Morin . . . . . . . . Euxantlione . . Tin. Chroniium. Red-brown ..... , , ..... , , ..... Olive-yellow .... Green - yellow, dull and pale Dull brown, yel- low ......... Brown-orange .... Brown-orange, in- clining to red Brown-orange, in- clining to gellow Dull yellow....... Bright yellow tint, rery pale, scarcely dyed Bright yellow, pale Bright red-orange. Slightly less red. Bright orange. Bright yellow. Cream colour, scarcely dyed. Bright yellow tint, very pale, scarcely dyed. Xyricetiii 8uZpphnte.-In order to determine the molecular weight of myricetin, its behaviour towards mineral acids was studied, this method, a s shown in former communications, having proved of con- siderable service for this purpose. The addition of sulphuric acid to myricetin suspended in boiling acetic acid caused the formation of an orange-coloured, crystalline compound, which was collected, washed with acetic acid, and dried. 0.1336 gave 0.2120 CO, and 0.0425 H,O. C = 43.27 ; H = 3.53. 0.1273 ,, 0.2020 ,, ,, 0.0345 ,, C = 43.67; H = 3.01.C15Hl,0,,H,S0, requires C = 43.26 ; H = 2.88 per ccnt. It was obtained as a glistening mass of slender needles somewhat redder than the corresponding quercetin compound. By treatment with water, it is decomposed into myricetin and sulphuric acid, as the following resnlt shows. Cl,HloO, = 76.85 ; S = 7-71. 0.4892 gave 0.3760 ClaHl0O, and 0.2747 BaS04. C15Hlo08,H2S04 requires C15HloOs = 76.44 ; S = 7.69 per cent. Xyicetin hydrobromide is obtained in orange-red needles on adding 0.1256 gave 0.2057 CO, and 0.0385 H,O. C = 44.66 ; H = 3.39. 0,1417 ,, 0,2358 ,, ,, 0.0417 ,, C = 45.38 ; H = 3.25. 0.1258 ,, 0.2095 ,, ,, 0.0318 ,, C = 45.41 ; €3 = 2.81. C15HT,,0,,HBr requires C = 45.11 ; H = 2.75 per cent. By treatment with water, it is decomposed into myricetin and hydrobromic acid, as the following result shows.0.4590 gave 0.3690 C,5H,008 and 0.2120 AgBr. Br = 19.64. hydrobromic acid to myricetin suspended in boiling acetic acid. ClsH,,08 = 80.39 C15Hlo08,HBr requires CI,HlOO, = 79.69 ; Br = 20.05 per cent.CONTAINED IX THE BARK O F 3lYRICA NAGI. 1291 N y f i c e i i n izydi*ochZoride, CI,H,,08,HCI, closely resembles the above compound. When heated a t looo, it is slowly decomposed into myricetin and hydrochloric acid, and was consequently not analysed. In the instability of its compound witli hydrogen chloride, mjricetin resembles quercetin, fisetin, and morin (Trans., 1895, 67, 646), but differs from that of luteolin (this vol., p. 208), which is stable atl this temperature. Jlyricetin Jzycl&dide, C15H1006,HI, crptallises beautifully in gI isten- ing needles of a red orange colonr. The above results show that the true formula of myricetin is C15H1008.HezacetyZmZlricetirL.-~ solution of one part of myricetin and one part of anhydrons sodium acetate in three parts of acetic anhydride mas boiled for one hour, the product poured into water, and, after being allowed to stand 24 hours, collected and purified by crystallisa- tion from alcohol. 0.1162 gave ij.2420 C'O, and 0,0448 H,O. It forms a silky mass of colourless needles melting at 203--204O, very sparingly soluble in alcohol, more readily in acetic acid. It is insoluble in cold alkaline solutions. I n order to determine the number of acetyl groups present in this substance, a solution in acetic acid was boiled with the addition of a few drops of sulphuric acid.Boiling water was then added, and the crystals of myricetin which separated on cooling were collected and weighed. C = 56.80 ; H = 4.27. C15H40b(C2H30)6 requires C = 56-84 ; H = 3.86 per cent. 0,8350 gave 0.4580 CI5Hl0O8. C15H,008 = 56.04. C15H40,(C2H30)6 requires C15H,,08 = 55.79 per cent. c15H508( H 3 0 ) 5 ,, = 60.22 ,, 77 It was therefore a hexacetyZ compound. Hexnbenzoy1rnyricetin.-Owing to the readiness with which myri- cetin decomposes in alkaline solution, the method of Baumann and Schotten was not available. Myricetin was therefore heated with excess of benzoic anhydride a t 160-170° for four hours, and the pro- duct dissolved in acetic acid and poured into alcohol. After 12 hours, it colourless precipitate had separated, which was collected, washed with alcohol, and purified by crystallisation from this solvent.0.1005 gave 0.2663 CO, and 0.0353 H,O. It was obtained as colourless needles, readily soluble in acetic acid, sparingly in alcohol. Action of Fused A l k d i s on Myricefin.-Mjricetin was heated with 10 times its weight of potassium hydroxide a t 150-170° until the melt, which was originally of an orange colonr, had become brown. It was then dissolved in water, the solution neutralised with C = 7226 ; H = 3.90. C15H408(C7H50)6 requires C = 72-61 ; H = 3-60 per cent.acid, extracted with ether, the extract evaporated, and the crys- talline residue dissolved in a little hot water.. On adding lead acetate, a relloaish-white precipitate wns formed, which was col- lected, and washed witli hot water, the filtrate being placed aside f o r further examination. The lead precipitate, suspended in a little water, was deconlposed by sulphuric acid, the lead sulphate renioved by filtration, the filtrate extracted with ether, and the extract eraporatcd.The brown residue, which became crystalline on standing, was treated with a very little hot water, in which most of it dissolved, the small quan- tity of insoluble product being collected. This, 011 examination, was found to be a trace of unaltered myricetin, and it is strange that 2ny of this substauce, which is so readily decomposed in dilute olka- line solution, should ha\ e resisted the ection of concentrated alkali a t such a high temperature. The filtrate, on standing, deposited crystals, which, after being drained upon a porous tile and crystallised two cr three times from boiling water, formed a mass of neeclIes of n slightig brown tint, nieltiiig a t 239--240°, with evolution of gas, and giving the reactions of gallic acid with ferric chloride.As, however, the rcac- tions of phloroglueinolcar.boxylic acid are very similar, according to Will and Albrecht (Ber., 1884, 17, 2103; 1885, 18, 132;3), i t was riecessary t o institute further tests. It was found that the substance3 dyed iron mordanted calico like gallic acid, that it did not give with fir wood and hydrochloric acid the phloroglucinol reaction, and, further, that when heated to 240' the residue had the properties of pyrogallol, and not of phloroglucinol. The filtrate from the lead precipitate was treated with sulphnric acid to decompose lead compounds, the lead sulphate removed by filtration, the filtrate extracted with ether, and the extract evapo- rated.The residue thus obtained was too smail for complete purifi- cation, but it gave the phloroglucinol reaction, and without dou!)t consisted chiefly of this substance. The principal products of the action of fused alkali on myricetin are therefore gaZZic acid and phloroglnci 1101. Action of Bromine on Jfyiicefi?t.-To a thin paste of myricetin in acetic acid, the amouut of bromiiie necessary for the formation of a tetrabromo-compound was added. Hydrogen bromide was evolved, and a clear solution gradually formed; this, after standing over night, was poured into about six times its bulk of water.At first crystals were slowly deposited, but after some time a small quantity of flocculent matter also separated. The product was collected and purified by several crystallisations from dilute acetic acid. As the yield obtained in this way was somewhat unsatisfactory, experiments It was therefore gaZZic acidCONTAINED IN THE BARK OF JIITRICA NAGI. 1293 were carried out on the bromination of myricetin suspended i n carbon bisulphide a t 100'. By this means the quantity of product obtained was found to be considerably increased. 0-1275 gave 0.2325 CO, and 0.0155 H,O. C = 28.34; H = 13.5. 0.2373 ,, 0.2790 AgBr. Br = 50.02. C,,H,O,Br, requires C = 29-47 ; H = 0.63 ; Br = S0.63 per cent. It was obtained in the form of brownish-orange, prismatic needles, melting and decomposing at 235-240°, readily soluble in acetic acid, slightly less so in alcohol.Alkaline solutions dissolve it at first with a jellow coloration, which on exposure to air becomes red, and finally passes into dirty brown. Its alcoholic solution gives with ferric chloride a deep blue coloration. With mordanted calico, i t dyes shades considerably yellower than those of myricetin itself, and more resembling those yielded by gallacetophenone. Although the analytical numbers agree closely with those required by tetrabromomyricetiu, and moreover the production of such a com- pound is in harmony with the probable constitution of this snbstance, j e t on account of the peculiarity of its properties considered side by side with those of the bromine derivatives of quercetin, morin, and luteolin, some little doubt must be entertained as to its identity until a molecular weight determination can be carried out.By the intro- duction of bromine into tlie above colonring matters, their reactions with ferric chloride are but little altered, moreover these compounds are considerably 1 ess soluble than the colouring matters themselvcs. I n examining the results of this investigation, but little donbt can be entertained that myricetin is a member of the quercetin series. I t s formula, its reactions with mineral acids, and the number of hydroxyl groups i t contains, when considered wiOh the results of its decomposition with alkali, are all in harmony with this sugges- tion. Moreover, its dyeing properties are very similar to those of quercetin and fisetin.* Before absolutely deciding its constitution, i t will be necessary to examine its methyl and ethyl ethers and their decomposition products ; unfortunately, the difficulty of iso- lating sufficient substance for this purpose may delay this investiga- tion for some time.There appears, however, every probability that myricetin, CI5H,,O,, will thiis be shown to hare the constitution of an hydrox y-querce t i n , 0 OH * Quercetin and fisetin both contain a atechol, and myricetin a hydroxjeatechol I n place of this, morin, on the other hand, possesses ft. (pyrogallol) nucleus.1294 COLOURING PRINCIPLE OF THE BARK O F RlYRICh NAOT. average I t s colour reactions in alkaline solution are evidently due to the oxidation of the pyrogsllol nucleus it contains.Tamiii Mcztter.-We are indebted to Mr. H. R. Proct,er, Lecturer on Leather Industries, Yorkshire College, for the following, an of four separate analyses of the bark of Myrica nagi. Tannin matters absorbed by hide ........ Soluble non-tanning substances. ......... 7.9 27.3 Fibre and insoluble matters.. ............ 52.3 Moisture. ............................. 12.5 100.0 - Dyeing Properties.-The tinctorial power of the product now examined was much less than that of the small sample of bark with which the earlier experiments were made, and which had a mucb snioother exterior, and was labelled ilfyrica rubra ; moreover, i t gave somewhat different shades with the different mordants. On Etriped mordanted calico, the present sample gave with alumina a comparatively dull yellow, inclining t o pink on a weak mordant, and with iron a purplish-grey, as if tannic acid were present. It,s colour- ing power w-as much less than that of old fustic and quercitron bark.On the other band, out’ former sample gave with alumina a full yellow, distinctly stronger, although somewhat duller, than those given by the dgewoods just mentioned, and the colour with iron mordant gave little or no indications of the prcsence of tannic acid. On wool mordanted with chromium, aluminium, and tin, and dyed with 40 per ceut. of our latest sample, greenish-olive, olive-yellow, and yellow colours respectively were obtained, all very pale and dull, whereas with the same mordants our former sample yielded deep olive yellow, dull yellow, and bright red-orange, the two first remind- ing one oE the corresponding colours obtained from quercitron bark, the latter being very similar to those given by Persian berries. These results show either that the colouring properties of Myrica nagi are somewhat variable, according to the age of the tree or branch from which the bark is taken, or that there may be different species of &fyricn, each with slightly different tinctorial properties. The com- parative richness of some of the barks, however, warrants DS in direct- ing the attention of native dyers of India to its probable utility as a yellow dye-stuff. Clothworkers’ Research Laboratory, Dyeing Department , Y o r kshire College. resorcinol group, and its distinctive dyeing properties wlicn compared with the above three colouring motters must be due t o this fact.

ISSN:0368-1645    

DOI:10.1039/CT8966901287

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年代:1896

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1295 LXXVIr.-Occzcl.?.e~lce of QuemetiiL in the Outer Skins of the Bulb of the Onion (Allium cepa). By ARTHUR GEORGE PERKIN and JOHN JAMES HubIMEL. 11 has long been the custom to use the outer dry skins of the bulb of the onion for dyeing Easter eqgs; for this purpose the eggs are wrapped in the skins, the latter being kept in position by tying with thread or otherwise, after which the eggs are boiled in the usual manner. By this means a marbled or mottled pattern is obtained i r i various shades of brown, orange, and yellow. The effect thus produced seemed to indicate that onion skins probably contain a yellow adjective colouring matter towards which, i n the custom alluded to, the lime oE the egg shell acts as a mordant. To test this point, a piece of ordinary striped mordanted calico was dyed for about ten minutes a t a boiling heat with onion skins, when the aluminium mordant became a full bright yellow, the iron mordant a dark greenish-olive.Samples of wool mordanted with chromium, aluminium, tin, and iron, were also dyed with onion skins, the colours obtained being respectively brownish-olive, yellow, bright orange, and greenish-olive. These results proved that this supposition was correct, and finding by further comparative dyeing experiments that the colouring power of onion skins was quite equal to that of such well known dye-stuffs as old fustic and yuercetin bark, it seemed desirable to ascertain, if possible, the nature of the colouring matter, and so determine whether or not it is identical with any existing mordant colouring matter.At the time of making these preliminary experiments, we were not aware that onion skins had ever been used for the purpose of dyeing textile materials, but 1 he following passage, translated from Leuch’s Farben und Fa?-bekzcnde, 1, 434, (1825), shows that they were formerly so employed, probably, however, only to a limited extent, and in districts where the art of dyeing was still practised as a home industry :-“ The outer skins of onion bulbs which are of a brownish- orange colour, have long been used in German households f o r djeing Easter eggs yellow, and in conjunction with alum, for dyeing woollen, linen, and cotton materials. The colour yielded is fast and particularly brilliant. According to Kurrer’s observations, onion skins are very suitable for dyeing cotton, on which they give a cinnamon-brown with acetate of alumina, a fawn with alumina and iron, a grey with iron salts, and a variety of shades with other additions.”1296 PERKIN ASD HUMMEL : OGCURREXCE OF QUERCETIN The colouring matter was extracted by boiling the onion skins (500 grams) for one hour with distilled water (9 litres).The yellow liquor thus obtained was strained through calico and allowed to cool over-night, when the impure colonring matter was deposited in tho form of a pale olive precipitate. Several kilos. of skins were treated in this manner, and by extracting three times with wat,er instead of once only, the yield of crude colouring matter was in- creased, the average yield of dry precipitate being about 1.3 per cent.on the weight of onion skins. The filtered orange-brown liquors when concentrated did not deposit any further pyecipitate on cooling, they were, therefore, evaporated to dryness, and yielded a considerable quantity of a brown, friable, resinous, dry extract. The finely ground, impure colouring matter was digested with boiling alcohol, filtered to remove a brown, insoluble product, and the filtrate evaporated to a small bulk. On cooling this solution, crystals were deposited, but as they were contaminated with a wax- like substance, and could not be readily purified by recrystallisation, the hot alcoholic liquid was poured into a large bulk of ether, and t'he mixture washed with water until colourless washings were obtained, and a sticky, black product no longer separated.On extracting the ethereal solution with dilute alkali, the whole of the colouring matter was removed, the was remaining dissolved in the ether ; on neutralising the alkaline liquid, a yellow precipitate was thrown down, which was collected and purified by c~ystallisation from dilute alcohol. C = 59.36 ; 0.1088 dried at 160' gave 0.2368 COzand 0.0355 H,O. H = 5-62. C,,H,,O, requires C = 39.60 ; H = 3.32 per cent. The substance was obtained as a glistening mass of yaliow neeJles sparingly soluble in boiling water, readily in alcohol. I t s alcoholic solution gives with lead acetate, an orange-red precipitate, and with ferric chloride a dark green coloration. When suspended in boiling acetic acid and treated with mineral acids, crystalline compounds were obtained, which by the action of water became decomposed into the colouring matter and free acid.I n order to ascertain its mole- cular weight, the sulphuric acid compound was analysed. 0,1295 gave 0.2158 CO, and 0.0343 H20. Its true formula was, therefore, C,,€I,,Oi. It was converted into its acetyl compound by digestion with acetic anhydride and anhydrous sodium acetate in the usual way, The product, when crystallised from alcohol, formed colourless needles melt,ing at 190--19lo. C = 45.4A ; H = 2.96. C15H1007*H2S01 requires C = 45.00 ; H = :3-00 per cent.IN THE OUTER SKINS OF THE BULB OF THE ONION. 1297 0.1221 gave 0.2622 CO, and 0.0437 HzO. C,5H507(C2H,0)5 requires C = 58.59 ; H = 3.90 per cent. To determine the number of acetyl groups present in this com- pound, it was decomposed by sulphuric acid in acetic acid solution, water being then added and the regenerated colouring matter collected and weighed.C = 58.56 ; H = 3.97. 1.0236 gave 0.6075 C&t&. It therefore contained five hydroxyl groups. Actiovl of E'used AZkaZi.-The colouring matte;. was heated at 150-170" for half an hour with a solution of ten times its weight of potassium hydroxide in a little water. The product was dissolved in water, the solution neutralised with acid, extracted with ether, and the crystalline residue remaining after evaporation of the ether, dis- solved in water and treated with lead acetate solution. A colourless precipitate was thus formed, which was collected, suspended in water and decomposed in the usual manner.From the aqueous liquid, by extraction with ether, a product was obtained which crystallises from water in colourless needles, melting at 195" and giving with ferric chloride in aqueous solution a green coloration. It was evidently protocatechuic acid. The filtrate from the lead salt of the above acid was found to contain phloroglucinol. Dyeing experiments were carried out with the colonring matter, using striped mordanted calico, and wool mordanted with chromium, aluminium, iron, and tin. The shades obtained were identical with those given by quercetin. The above results prove conclusively that the colouring matter of onion skins is querceti?i. It may be mentioned that though no further confirmation is necessary, a bromine derivative was prepared which had all the properties of dibromo- quercetin.As above shown in the identification of this substance considerable pains have been expended, and this was considered necessary on account of the close similarity in external properties of the various known colonring matters of the queincetin group, and also the slight differences between the melting points of their derivatives. Numerous isomerides of quercetin have yet to be discovered and reasoning by analogy, these will probably possess very similar properties. It is interesting to note with regaid to the quercetin group, that whereas fisetin is only known a t present to exist in young fustic (Rhus cotinus), luteolin in weld (Reseda Zzsteola), morin in old fustic and jackwood (Morus tinctoria and Artocaipus iqhteyrifolin), and rhamnetirl and rhsmnazin in Persian berries, quercetin itself has a much more widely distributed existence. For instance, it has been found present C15H100, = 59-34. Cl,H507(C2H30)5 requires Cl,HloO, = 58.98 per cent. VOL. LXIX, 4 R1298 NEWTH: AN APPARATUS in quercitron bark, Persian berries, catechu and in tea leaves ; also in the bark of the apple tree and horse chestnut, and in numerous other natural products. That this coincidence is more apparent than real is possible, for there are indications that this is so in further work that is being carried out in this department on the yellow colouring matters of numerous plants. Clothzcorkers’ Besearch Laboratory, Yoi*kshire College. Dyeirq Department,

ISSN:0368-1645    

DOI:10.1039/CT8966901295

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年代:1896

数据来源: RSC

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1298 NEWTH: AN APPARATUS LXXVIIL-An Apparatus for showing Experiments zvith Ozone. By G. S. NEWTH. B THIS aspparatus has been designed to show the contraction which takes place when oxygen is converted into ozone, and also the effect on the volume which results from the action of certain re- agents on the ozonised oxygen. The ap- paratus differs from others which have been constructed for the same purpose, only in the device which has been adopted for introducing the reagent without dis- turbing the volume of the gas. The inner tube of the apparatus is an elon- gation of the stopper, and has upon its side two little " pimples," a, a, abont an inch apart in a vertical line. The outer tube has two similar " pimples," b, b, projecting inwards, and placed near to- gether in a horizontal plane.The re- agent is contained in a fine, sealed glass tube, d, which is laid between the two points b, b, and held in position by the projections a, a, as in a clutch. Oxygen is admitted through the cock C, pawing out through B ; the apparatus is then placed in ice and water, and atmospheric pressure restored by ad- mitting a little more oxjgen through C.FOR SHOWIXG EXPERIXENTS TITH OZONE. 1299 One wire from the induction coil dips into the dilute acid in the elongated stopper, whilst the other dips into the ice and water. The contraction in volume which results upon ozonising the oxygen is indicated by the change of level of the liquid (sulphnric acid) in the little manometer, an image of which is thrown upon the screen. By twisting the stopper, the fine tube containing the reagent is crushed, without any disturbance of the level of the liquid in the manometer. If the reagent used is turpentine, it is possible to show with this appratus that the contraction in volume due to the absorp- tion of the ozone is twice as great as that which takes place whenthe oxygen is ozonised. I€, on the other hand, the reagent is such an one as potassium iodide, the apparatus enables one to demonstrate, that whilst iodine is liberated, the volume of the contained gas undergoes no alteration.

ISSN:0368-1645    

DOI:10.1039/CT8966901298

出版商:RSC    

年代:1896

数据来源: RSC

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FOR SHOWIXG EXPERIXENTS TITH OZONE. 1299 LXXIX- Colouring Mattefa of Siciliccn Sumach, Rhus Coriaria. By ARTHUR G. PERKIN, F.R.S.E., and GEORGE YOUNG ALLEN. IT is well known that numerous tannin matters such as sumach, catechu, divi-divi, &c., dye fabrics mordanted with aluminium pale yellow shades, and this, taken in conjunction with the dark bluish- black that they yield with iron mordant, has frequently been con- sidered a s a property of the tannin substance they contain. As numerous members of the tannin class have been but superficially examined, and many of their principles have probably not yeti been obtained in a pure condition, some of these, i t is possible, may behave as mordant yellow dye-stuffs : on the other hand, however, Lowe has stated that both catechu and sumach contain quercitrin and quercetin (Zeit.anal. Chem., 1874, 12, 127), and i t is thus evident that, in some cases at least, this dyeing property is due to the presence of a distinct colouring matter rather than to the tannin itself. Wit8h the object of determining how far this is t.he case, and with the desire of ascertaining the class of colouring matters they contain, such as are available are undergoing investigation. Sumach consists of the dried and powdered leaves of the genus Rhus (order Terebinthacae), especially R. corkria and R. cotinus. The former constitutes Sicilian sumach, the best known and most fie- quently used variety, the latter Venetian sumach, and i t is interesting to notice that it is the wood of this tree (B. cotinzu) whichconstitutes young fustic, the tinctorial properties being due to fisetin.Sumach is useful for tanning the finer kinds of leather, and also in dyeing and VOL. LXIX. 4 s1300 PEREIN AND ALLEN: calico printing on account of the tannin matter present in it. According to Chevrcul, it contains a yellow coIoui*ing matter which separates in crystalline grains from a concentrated decoction on cool- ing (Wutts’ Diet. Chem., 1874, 5, 614). We were unaware at the commencement of this investigation that Lowe (Zoc. cit.) had preriously investigated this subject ; had this been the case its re-examination would probably not haFe been attempted. I n his paper, “ Ueber dns Vorkomrnen des Quercetins und Quercitrins in Catechu und Sumach,” Liiwe states that from the different varieties of sumach, yellow, crystalline substances can be obtained if these be extracted with methylated spirit, and the extracts evaporated and treated with water.Crystals are thus obtained which differ from quercetin in that they are soluble in a large volume of boiling water, and this solution, on cooling, redeposits them, sometimes in needles, but more often in yellow flocks. Sicilian sumach was found to conhain them in somewhat greater quantity than the other varieties. An average of the analyses of the products gave C = 52.60; H = 4.83 per cent., and they had further the pro- perties of quercitrin. Our investigation shows that Sicilian sumach contains neither quercitrin nor quercetin, but the colouring matter described below, and the difference between our results and those of Lowe can only be accounted for by the supposition that either his sample of Siciliai; sumach was not genuine, or that the close resem- blance between the appearance of this colouring matter and that of quercitrin caused him to believe them to be identical.The tannin of sumach has also been investigated by Lowe, who found it to be identical with the gallotannic acid contained in nut- galls. One thousand grams of ground Sicilian sumach was extracted for p i x hours with ten times its weight of boiling water, filtered through calico, and the filtrate, while still hot, treated with a solution con- taining 55 grams of lead acetato ; the precipitate, which at first was pale yellow, on contiuued boiling, gradually became dirty white, and as on examination i t was found to contain no colouring matter, but to consist almost entirely of a lead compound of the tannin matter, it was removed by filtration and washed with hot water. To the filtrate, excess of lead acetate solution was now added, the yellow precipitate thus formed being collected, washed with water, suspended in boiling water, and decomposed with dilute sulphuric acid.After removal of the lead sulphate, the clear liquid was extracted with ether, the ethereal extract evaporated to dryness, the crystalline residue dissolved in alcohol, and the solution treated with boiling water. On cooling, a, small quantity of a crystalline matter separated, which wasCOLOURISG MATTER OF SICILIAN SUJIXCEI. 139 1 collected, bat as it was evident that by this treatment the quantity of the original product had cnnsiderabIy decreased, the filtrate was reserved for further examination.The residue was purified by crystallisation from dilute alcohol. The yield was 1.173 gram, o r 0,1173 per cent. C = 56.69; H = 3.61. 0*1230, dried at 160°, gave 0.2557 COz and 0.0400 H20. C,,H,,08 requires C = 56-60 ; H = 3.14 per cent. It was obtained as a glistening mass of light yellow needles, closely resembling quercetin in appearance, b n t was readily dis- tinguished from the latter by its reaction with solutions of t'he alkali hydroxides. Dilute potassium hydroxide dissolves it w i t h a green coloration which, on exposure to or shaking with air, rapidly assumes a deep blue t i n t ; this, in its turn, gradually changing to dull violet.Strong alkali dissolves it with an orange-yellow colora- tion, which is fairly permanent ; this solution, on dilution, becomes green, and passes through the colour changes recorded above. With lead acetate in alcoholic solution, an orange-red precipi tatte is formed, whilst alcoholic ferric chloride gives a brown-black coloration. Upon wool mordanted with chromium, aluminium, and t i n , it gives respec- 1 ively red-brown, brown-orange, and bright red-orange shades, which closely resemble those obtained from quercetiti and fisetin in a similar way. Sulphuw'c acid Compo2cnd.-When treated with mineral acids in the presence of acetic acid, the colouring matter yielded orange to orange-red crystalline compounds, readily decomposed by water. The sulphuric acid compound was analysed.0.1278 gave 0.2037 C02 and 0.0350 H,O. C,5H1008,H2S04 requires C = 43.26; H = 2-58 per cent. AcetyZ CompozmL-In order to prepare the acetyl compound the colouring matter was digested with three parts of acetic anhydride and one of anhydi*ous sodium acetate at the boiling point for one hour, The product was poured into water, and after standing 12 hours, the precipitate was collected and crystallised from alcohol. C = 43.46 ; H = 3.03. 0.1201 gave 0.2497 CO, and 0.0420 H20. C,,H40,(C2H,0), requires C = 56.84 ; H = 3-86 per cent. It was obtained as colourless needles, melting a t 203-204', and sparingly soluble in alcohol. Action of Fused AZkaZis.-The colouring matter was heated at 150-170' for half an hour with 10 times its weight of potassium hydroxide dissolved i n a little water.The melt was dissolved in water, neutralised with acid, extracted with ether, the extract evapo- C = 56.70 ; H = 3.88. 4 s 21302 COLOURING MATTER OF SICILIAN SUMACH. rated, and the residue dissolved in a little boiling water a,nd treated with lead acetate solution. The precipitate was collected, washed with water, decomposed in the usual way, the clear solution extracted with ether, and the extract evaporated. The residue, when purified by crystallisation from water, was obtained as needles melting a t 235" t o 240", with evolution of gas. The filtrate from the lead precipitate WRS treated with sulphuric acid to decompose lead compounds present, extracted with ether, and the extract evaporated. The residue left was too small for complete purification, but as its aqueous solution gave, with fir-wood and hydrochloric acid, the phlorog Zuczhoi! reaction, it evidently contained this substance.From these results it is evident that the colonring matter of Sicilian sumach is myricetin, C15H1008, which, as demonstrated in a It was found to be gallic acid. preceding paper, exists in the Indian dye-stuff, Myrica nagi (this vol., p. 1289). The acetyl compound of this substance melts a t 203-204"; on fusion with alkali, it yields phloroglucinol and gallic acid, more- over, its dyeing properties are identical with those of the colouring matter of Sicilian sumach. It is remarkable that its existence in a product so laygely used should have been so long undetected, for although in external pro- perties it is very similar to quercetin, yet its characteristic reaction with dilute alkali at once distinguishes it from this coiouring matter.As previously stated, it was evident t.hat the ethereal extract obtained during the isolation of the myricetin contained a second substance distinguished by its ready solubility in dilute alcohol. The filtrate from the myricetin was, therefore, extracted with ether, the extract evaporated, and the crystals which separated from the residue on standing, collected and drained upon a porous tile. It was puri- fied by crystallisation from water. 0.1079 gave 0 1972 CO, and 0.0350 H,O. C = 49.84 ; H = 3.60. 0.1216 ,, 02223 ,, ,, 0.0406 ,, C = 49.85; H = 3-70. C1H,05 requires C = 49.41 ; H = 3.52 per cent. The product consisted of nearly colourless needles melting at 238-240°, with evolution of gas.With ferric chloride, in aqueous solution, it gave a blue-violet coloration, and when heated with sulphuric acid a t 140°, a product was obtained having .the reactions of rufigallic acid. It was evidently gallic acid. I n order to determine whether myricetin existed in this sample of sumach chiefly in the free state, or whether its isolation in theCOLOUHING RIATTER OF QUERBRACHO COLORADO. 1303 manner above described was due to the decomposition of a glucoside, an aqueous extract mas extracted with ether. The residue obtained on evaporating the extract consisted principally of myricetin* and gallic acid, and in such quantity that it was evident that little or no glucoside could be present in the sumach. It is probable that in the fresh leaves a glucoside exists, for there seems to be little doubt that this is the original condition of all vegetable colouring matters. I n investigating the dyeing properties of sumach, wool mordanted with chromium, aluminium, and tin was employed. The shades pro- duced were respectively pale olive, olive-yellow, and pale yellow, but these were extremely weak when compared with the well-known natural yellow dye-woods. We feel it, desirable to reinvestigate the other varieties of sumach, and hope to do so if we can obtain them of guaranteed purity. Clothworkers’ Research Laboratory, Dyeing Department, Yorksh ire Ccl lege.

ISSN:0368-1645    

DOI:10.1039/CT8966901299

出版商:RSC    

年代:1896

数据来源: RSC

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COLOUHING MATTER OF QUERBRACHO COLORADO. 1303 LXXX.--The CoZou&g Ahtter of Querbracho Colorado. By ARTHUR GEORGE PEKKIN, F.R.S.E., and OSWALD GUNNEL[,. THE Qzce~bracho colorudo is an anacardiaceous tree growing in the northern part of the Argentine Republic, the wood of which consti- tutes the well-known tannin substance, “ querbracho.” It is as suitable as sumach for the production of Morocco leather, especially in the preparation of the darker colours, and it has dso been found useful, in conjunction with alum, for the production of the finer leathers, as i n this way it gives a bright yellow shade instead of the redder colours produced in the ordinary way. Jean (Bull. SOC. Chim., 1880, 33, 6) found that it contained 15.7 per cent. of a tannic acid not identical with that of oak bark or chestnut wood, and, according to Arnaudon (Watts’ Did. Chem., 8, l i 3 2 ) , there is also present a colouring matter which gives n fine yellow dye.The material employed in this investigation was an extract of Querbracho colorado, specially obtained for us, and in order that there might be no doubt as to its purity, application was made to Mr. H. R. Proctcr, Lecturer on Leather Industries, Yorkshire College, who * The myricetin obtained by merely extracting an aqueous decoction of the sumach with ether, was more difficult to purify than that obtained by the method described a t the commencement of this paper. Although apparently simpler, it was far less effective than the latter method.1304 PERKIN AND GUNKELL : THE COLOURINC: MATTER very kindly examined it, and found tbat its reactions were identical with those given by a decoction of the wood itself.The preliminary experiments on the isolation of the colouring matter were carried out by fractionally precipitating an aqueous solu- tion of the extract with lead acetate, this method having been found of considerable service for the isolation of the coloui*ing matters con- tained in Myricn lzagi (this vol., p. 1288) and Sicilian sumach (see preceding paper). By this means the presence oE the colouriug matter wzs detected ; but this was mixed with a wax-like substance, which could only be removed with difficulty, for the amount of colouring matter obtained was very small. Ultimately a new method was devised which gave better results. To a solution of 1,500 grams of the extract in 1,500 C.C.of water, 350 C.C. of sulphuric acid diluted with a little water was added, and the whole digested at the boiling heat. From the opaque liquid, a dark coloured, sticky product quickly separated in large quantity ; as soon as this had ceased t o be deposited, and the supernatant liquid was clear, t,he mixture was strained through calico, the filtrate extracted with ether, and the extract evaporated. During the evaporation, the solution gradually became opaque, and an orange-brown, crystalline powder commenced t o sepamte, and con- timed to do so until the whole became complately dry ; the residue was treated with boiling, very dilute alcohol, in wliich part only was soluble, and the mixture allowed to remain for 12 hours, during which time a pale yellow precipitate had separated.The whole was col- lected, and, after being washed with water (the filtrate C being re- served for further examination), was extracted with rz little hoiling alcohol (A) ; the small quantitF of an insoluble residue (B) which remained evidently consisted of tAhe crystalline matter referred t o above as separating from the ethereal solution during its evaporation. The alcoholic extract (A) was evaporated to a small bulk, treated with twice i t s volume of boiling water, and the crystals of the colour- ing matter, which were deposited on cooling, were collected and purified by recrystallisation from dilute alcohol. The yield of pure colouring matter obtained by this means averaged 0.25 gram from 1,300 grams of the extract, or 0.016 per cent.0.0944, dried a t 160°, gave 0,2168 GO, and 0.0318 H,O. C = 62-63 ; H = 3.74. C,,H,,O, requires C: = 62.91 ; H = 3.49 per ceut. It consisted of a glistening mass of fine yellow needles, readily soluble in alcohol, more sparingly in ether. Alkaline solutions dis- solved it with an orange-yellow coloration, and, when treated w i t h lead acetate in alcoholic solution, an orange-coloured precipitate wasOF QUERBRACHO COLORADO. 1305 obbained. With alcoholic ferric chloride, i t yielded a dark green coloration. On treatment with mineral acids in the presence of acetic acid, orange-red, crystalline acid compounds were produced ; but the amount of material at our disposal was so exceedingly small that we were unable to prepare sufficient of these substances for analysis.OR calico mordanted with aluminium and iron, it gave respectively bright orange, and dark greenish, olire-coloured shades. Benzoy l Compound.-The colouring matter was heated with excess of benzoic anhydride a t 170-175' for four hours, the product dis- solved in acetic acid, and poured into a large volume of alcohol, After 12 hours, a colourless precipitate had deposited which was col- lected, mashed with boiling alcohol, and crystallised from a mixture of alcohol and chloroform. 0.1316 gave 0.3540 COz and 0.0483 HzO. C15H606(C,H50)4 requires C = 73.50; H = 3.70 per cent. It, crystallkes in colonrless needles melting a t 180-181°, almost insoluble in alcohol, but readily in chloroform, acetone, and benzene. Acetyl Compound.-A mixture of three parts of acetic anhydride, one part of anhydrous sodium acetate, and one of the colouring matter was digested at the boiling point for one hour; the liquid was then poured into water, and, after standing 12 hours, collected, and crystallised from alcohol.It formed oolourless needles melting a t 196-19B0, sparingly soluble in alcohol. C = 73.36 : H = 4-07. 0.1197 gave 0.26i6 COzand 0.0443 H20. C,5H606(C2H30)a requires C = 60.79; H = 3.96 per cent. Fusion with AZkaZi.-0-4 gram of the substance was heated a t 170-200" for half an hour with 10 grams of potassium hydroxide dissolved in a little water, and the melt was then poured into water, neutralised with acid, the products of the action extracted by means of ether, and dissolved in a little water.The addition of lead acetate to this solut,ion caused the formation of an almost colour- less precipitate, which was collected, suspeiided in water, and de- composed with dilute sulphuric acid. After removal of the lead sulphate by filtration, the filtrate was extracted with ether, the ex- tract evaporated, and the residue purified by crystallisation from water. The product consisted of needles melting at 194-195', the aqueous solution of which gave a green coloration with ferric chloride. There could be little doubt that this substance was proto- catechzcic acid. To the filtrate from the lead precipitate, snlphnric acid was added, the clear liquid decanted from the lead sulphate, extracted with ether, and the extract evaporated. A very small quantity of a residue was obtained, which in aqueous solution gave a violet colorat.ion with C = 60.97; H = 4-11,1306 PERKIN AND GUNNELL: THE COLOURINCT MATTER ferric chloride; to further purify it, it was distilled in a test-tube, and the crystalline product again sublimed between watch glasses.The crystals obtained melted at 1OO-l0lo, and appeared to consist, of YesowinoZ, although not quite pure, as a sample of this from Kahl- banm melted at 108--109°. It is interesting to note that the presence of phloroglucinol could not be detected among the products of the reaction. The colouring matter present in Querbrncho colorado mas, therefore, apparently fisetin, Cl5HlOO6, and to corroborate this a small quantity was prepared from young fustic (Rhus cotinus) and the two substances compared eide by side as regards their dyeing properties.As a result no difference coiild be detected in the shades obtained, and moreover the two products appeared identical as regards their general properties. The melting point of acetylfisetin, C,5H60s( C,H,o),, is given by Herzig as 196-199', by Schmid (Bey., 1876, 9, 1742) as 200-201", and that of the benzoyl derivative as 184-1535' by the latter chemist. As our benzoyl compound melted, how- ever, four degrees lower, 180-181", some benzoylfisetin was prepared. and thiR was found to melt at 181-182"; this small difference of one degree can readily be accounted for, if our product con- tained some trace of an impurity, for the small quantity available did not admit of its subjection to any special purification.I n fact the total amount of colonring matter at our disposal for this investiga- tion was but from 1.3 to 1.5 gram. There can, therefore, be but little doubt that this substance is Jisetzln, which it is interesting to notice has previously only been known to exist in Rhus cotinus. Insoluble residue B.--The orange-brown, crystalline product re- maining undissolved in alcohol during the purification of the fisetin waa found to be so sparingly soluble in solvents that it could not be further purified. It was, therefore, analysed in this condition. 0.1256 gave 0.2295 CO, and 0.0385 H,O. CIPHIOOIO requires C = 49.70 ; H = 2.96 per cent. This substance, which under the microscope had the form of thick prisms, was almost insoluble in boiling acetic acid, alcohol, and nitro- benzene, but soluble in dilute alkalis with an orange coloration which on exposure to air became somewhat redder in tiut.If dissolved in boiling very dilute alcoholic potash, and the solution neutralised with boiling acetic acid, a nearly colonrless precipitate separated, which under the microscope appeared as fine needles. If this con- sisted of the original eubstance, as appeared to be the case, i t still being but little attacked by solvents, this method would be available for its purification, but with the small quantity at our disposal we hesitated to adopt it. Suspended in alcohol and treated with ferric C = 49.13 ; H = 3.40.OF QUERBRACHO COLORADO. 1307 chloride solution, it was coloured first green and then blue-black, and when added to nitric acid and the solution diluted with water, a deep red liquid was obtained.This substance had, therefore, the properties of eZZagic ncid with one of the formula assigned t o which (CldH1,O,O, or C14H,0,,HzO) the above analysis agrees fairly well. Judging, however, from the properties of ellagic acid, it is highly probable that its molecular weight is considerably higher than that represented by this formnla, and we hope shortly to commence an investigation on this interesting substance. Ellagic acid has been previously found in divi-divi (Lowe, Zeit. anal. Chern., 1875, 14, 40), and in mir'a- bolans, oak bark, and various other tannin matters, where it appears to exist in the form of what is known as ellagi-tannic acid from which ellagic acid is produced by heating at 110'.As far as we are atvare ellagic acid has not been previously shown to exist in the Qzcerbracho colorado. The agueozcs Jiltrate, C , obtained during the purification cf the crude fisetin (p. 1304) was extracted with ether, the extract evapo- rated, and the residue treated with a little hot water. On cooling, a semi-solid crjstalline mass was obtained which was collected by means of the pump, the residue dissolved in water, acd the solution sat'urated with salt which caused the precipitation of a brown, sticky, product ; after removing the latter by filtration, the filtrate was extracted with ether, and the residue obtained on evaporating the yellow extract was dissolved in water, and treated with sufficient lead acetate solution to precipitate about one-third of it. This was filtered off, the filtrate extracted with ether, and the product thus obtained finally purified by crystallisation from water. C = 49.16 ; H = 3.80. 0.1145, dried at 14OC, gave 0.2064 COz and0.0392 HzO. C7H605 requires C = 49.41 ; H = 3.52 per cent. I t formed a mass of colourless needles which melted at 235-240' with evolution of gae. Treated with ferric chloride in aqueous solution, a deep blue coloration was produced, and when heated with sulphuric acid at l4Oo, it was converted into a substance having the reactions of rufrgallic acid. It was evidently gallic acid, and its presence here in considerable quantity appeared t o be due largely to a decomposition of the tannin matter by the strocg acid employed for the isolation of the fisetin. Clothworkers' Besearch Laboratory, Dyeing Department, E'orkshire College.

ISSN:0368-1645    

DOI:10.1039/CT8966901303

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

1308 LXXXI.- The Chemical Ina,ctivity of Rontgen Rays. By HAROLD BATLY DIXON and H. BRERETON BAKER. THE authors have investigated the effect of X rays on some chemical actions, but the results have hitherto been negative. The source of the rays in most cases was a bulb of the form devised by Mr. Herbert Jackson. The bulb and coil were enclosed in a metal box, connected to earth, with an aluminium window just above the bulb. The sub- stances were enclosed in thin glass bulbs, provided with aluminium windows when the nature of the substance allowed the use of t h i s metal. When aluminium would have been attacked by the substance used, the containing vessels were bulbs so thin that they gave only A faint annular shadow on a screen OE potassium platinocyaiiide. The exposure was usually half an hour, the efficiency of the bulb being tested a t frequent interrala with the fluorescent, screen.The effect m7as tried on mixtures of (1) carbon monoxide and oxygen (dried and moistj ; (2) hydrogen and oxygen; (3) carbon monoxide and chlorine ; (4) hydrogen and chlorine ; (5) hydrogen sulphide and sulphur dioxide (dried). No combination, either explosive or gradual, occurred between the gases exposed. I n the case of the dried mixture of carbon mon- oxide and oxygen, sparks were passed through the mixture while it was exposed t o the Rontgen raps. Each spark prodnced slight com- bination in its path, but no difference could be detected in its action when the rays were falling on the mixture and when they were not. The combination of chlorine with carbon monoxide and with hydro- gen is effected by light.The rate of combination in both cases depends on the intensity of the light. It is easy to measure accu- rately the rate of' combination of these gases when combining slowly ; and then, on allowing the Rontgen rays to fall upon the mixtures, to observe any alteration in the rate of union. Dr. A. Harden, who is investigating the union of carbon monoxide and chlorine, was good enough to measure the rate of combination i n the presence and absence of the Roritgen rays. For the combination of chlorine and hydrogen, an apparatus somewhat similar to that used by Bunsen and Roscoe was employed. Not only did the Rontgen rays have no effect on hydrogen and chlorine in the dark, but they did not alter the rate of combination due to the action of light.The effect discovered by Pringsheim--a sudden expansiori and slow return of the gases to their original volume uiider the influence of the light from a bright spark-was also examined, in presence and absence of Rontgen rays. No differznce could be No difference could be detected.POSlTION-ISO3lERISll A XD OPTICAL ACTIVITY. 1309 detected. The Rontgen bulb in these cases seemed to act merely like a warm body mould do in its place.* A Rolution of sodiuni sulphite exposed to the rays showed no greater absorption of oxygen than a similar solution which was pro- tected. Hydrogen peroxide was apparently unaffected. The glowing of two pieces of phosphorus, one of which was exposed to the rays, and the other shielded by a thick piece of platinum, showed no per- cepti ble difference.I t was thought that, since the r a p cause electric discharge from metallic bodies, they might show some effect on electrolysis. A cell with an aluminium bottom was filled with distilled water, and con- nected with a battery and a delicate Thornson galvanometer. The latter was placed at some distance from the box containing the coil and bulb, acd =as shielded by a thick, earth-connected iron screen. KO effect was observable when the rays mere passed through the cell, and when, by the addition of a small quantity of sulphuric acid, the liquid became a conductor, the rays produced no sensible increase o r decrease in the coudnctivity of the liquid. Though the experiments described all gave negative results, it is probable that the rays may exert some direct influence on chemical action, only this result may be too sinall f o be measured. In the action on a photographic plate, which is believed to be chemical in its nature, i t must) be remembered thst a very small force will produce a result which is very apparent. The action of the X rays on a sensitive plate is probably caused either directiy, or by the fluorescence of the film. That it is not due to the fluorescence of the glass behind the film is shown by examining a section of the film with the microscope, when the deposit of silver is found to be entirely on the side of the film directly exposed to the rays,

ISSN:0368-1645    

DOI:10.1039/CT8966901308

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

POSlTION-ISO3lERISll A XD OPTICAL ACTIVITY. 1309 LXXXII. - P o s ~ t ~ o ~ ~ - ~ ~ o ~ e r i ~ ~ ~ and Optical Activity ; the Methylic and Ethylic Salts of ortho-, meta-, und ~ara-Ditoluyltal.tcL.ric acids. By PERCY FRBXKLASD, Ph.D., F.R.S., and FREDERrcK MALCOLM WHARTON, A.I.C., Priestley and late Porster Scholar in Mason College, Birmingham. THE object of the present investigation has been to ascertain the effect of position-isomerism on the optical activity of a substance containing a benzene ring. We have in the first instance selected * Our thanks are due to Professor Schuster and Mr. J. Burke for their assist - a w e in these experiments.1310 FRANKLAND AND WHARTON : tartaric acid, and have studied the effect of introducing the toluJ1 group in its three isomeric forms (ortho-, meta-, and para-) into met.hylic and ethylic tartrates.We have in fact prepared and examined the optical activity of six compounds, viz., methylic ditoluyltartrate (ortho-, meta-, and para-) and ethylic ditoluyl- tartrate (ortho-, meta-, and para-). The methylic and etliylic paraditoluyltartrates have already been prepared by Freundler (Thesis, Paris, 1894, 47), but their optical activity was only determined in alcoholic solution, whilst we have in all cases determined the rotation in the liquid skate and over a wide range of temperature. Preparation of Methylic and Ethylic Twtrates. These were prepared by the well known hydrochloric acid method, using the slight modification, introduced by Freundler, of producing in the first instance the acid methylic and ethylic tartrates.Thus, 50 grams of tartaric acid, which had been previously dried for three hours in a steam oven, were mixed in a flask with 100 grams of absolute alcohol (ethylic or methylic), and the mixture allowed to stand over night. The alcohol was then distilled off on it water bath, and the residual syrup transferred to a dish and placed for three hours in the steam oven. It was then again tyansferred to a flask, 100 grams of absolute alcohol added, and dry gaseous hydrogen chloride passed through to saturation, the flask being kept cool by immersion in cold water. Dry air was then bubbled through for about five hours, after which the liquid was placed in a dish over slaked lime in a vacuum desiccator for six days, so as to remove the greater part of the hydrogen chloride.The liquid was then distilled under reduced pressure (9 mm.) ; the alcohol passed over a t about 45O, and then the temperature suddenly rose t o 164', the ethylio tartrate (51 grams) passing over between 164' and 168'. Ti& crude product was then refirtctionated under reduced pressure until the rotation remained constant. The final products thus obtained exhibited the following rotations in the polarimeter. Methylic tartrate. . U D = + 2-74' (1 = 1, temp. = 20°, i n state of Nthylic ,, . . LZD = +9*30° superfu sion): Pyepai*ation of Ortho-, Meta-, and Para-toluyl Chlorides. As the ditoluyl compounds were in each case to be obtained by the action of the particular toluyl chloride on the methylic and ethylic tar- trates, it was in the next place necessary to prepare the three toluyl chlorides.This was in each case done by the action of phosphorus trichloride on the corresponding toluic acid.POSITION-I SORIER 1831 AND OPTICAL ACTITITY. 131 1 The orthotoluic acid (Kahlbaum) used melted at 102'. 50 grams weye placed in a Wurtz flask, the lateral tube of which was provided with a condenser, the flask was heated to 110" in an oil bath, and 18 grams of phosphorus trichloride gradually added from a dropping funnel. Hydrogen chloride was copiously evolved, and when all the phosphorus trichloride had been added, the flask was heated at 170" for 14 hour. On subsequent distillation, some excess of phos- phorus trichlorida passed over, after which the vacuum was applied, and the orthotoluyl chloride came over at 103" (8 mm.pressure). The product was found to contain some phosphorus compounds, and was therefore redistilled under reduced pressure, a little of that passing over first being rejected; the main portion came over at 102" ( 7 mm. pressure), and this was found to be free from phosphorus. The paratoluyl chloride was prepared in precisely the same way ; the paratoluic acid (Kahlbanm) used had a melting point of 1 7 8 . 3 O (corr.). The purified paratoluyl chloride passed over a t 107" (8 rnm. pressure). The metatoluic acid obtained from Schuchardt melted at 104*5', whilst the pure acid is said to melt a t logo. By repeated recrystslli- sation from water, the melting point was brought up to 108.5", further cry stallisation producing no change.The metatoluyl chloride was prepared in the same way as the ortho- and para-compounds described above ; it distilled at 109" (8 mm. pressure). Ethylic Orthoditoluyltnrtrate. Forty-two grams of orthotoluyl chloride were heated to 140°, and 14 grams of ethylic tartrate were then slowly added from a dropping funnel with constant agitation ; the toluyl chloride taken was twice that theoretically required to produce the ditoluyl compound. When the action was complete, the excess of toluyl chloride was distilled off under reduced pressure, whilst the product of the reaction came over a t 280' (7 mm. pressure). From the weight of the crude pi.0- duct (28 grams) it was at once apparent that it was the ditoluyl, and not the monotolujl compound which had been formed. This crude product was a syrupy liquid, possessing when cold a yellowish-green fluorescence.It was dissolved in ether and washed with a solution of sodium carbonate. All attempts to crystallise the substance, both by placing it in L vacuum desiccator as well as by the use of the most varied solvents, failed. It was redistilled and again washed with sodium carbonate, but without affecting its rotation, so that it was then submitted t o analysis, with the following results.1312 FRASKLAND AND WHARTON : 0.2344 gave 0.5579 CO, and 0.1261 H,O. C = 64.91 ; H = 5.97. 0.2212 ), 0,5272 ,, ,, 0.1811 ,, C = 65.00; H = 6.0s. C,rH,,Oe requires C = 65.16 ; H = 5-88 per cent,. The following density determinations of the ethylic orthoditoluyl- tartrate were made. d 30°/4" = 1.1705.d 47*8"/4" = 1.1567. d100'/4" = 1.1116. From these by extrapolation were calculated d 70'/4' = 1.1359. a i i o p o = 1.1867. d 1350140 = 1.0833. These densities enabled the specific rotation [ a ] D to be calculated for all these temperatures a t which the rotation was observed in rz jacketted polarimeter, the length of tube in each case being 44 mm. Rotation of Ethylic 01.tkoditoluyltnrtrafe. 7, - 60.37". -31.52' - - 0.44 x 1.1867 0-44 x 1%?% - 0.44 x 1.1567 0.44 x 1.1359 [a]= a t 11' = 30" = -60.33. -31.07" - -30.30" - 17 49-5-48' = - -59.53. --28*9i0 - 70" := - -57.96. 7 , -26.77" - -54.73. looo = 0.44 x 1.1116 The .influence of temperature on the specific rotation of this com- pound is graphically represented in the diagram, p. 1316. Methylic Orthoditoluylta~trate.This was prepared on the same lines as the ethylic compound described above. Forty-eight grams of orthotoluyl chloride and 14 grams of methjlic tartrate were employed, the mixture was made at 140°, the tempera- ture being finally raised to 180" for 20 minutes. In the subsequent distillation, the product, 37 grams of which were obtained, began distilling at 276", the greater portion passing over a t 280" (8 mm. pressure). Like the ethylic compound, i t was a fluorescent syrup, but after washing in ethereal solution with sodium carbonate, it was obtained in a crysta.lline form from methylated spirit ; the crystals were prismatic, somewhat resembling those of cane sugar. It isPOSITIOS-ISOMERIEhI AND OPTICAL ACTIVITY. 131 3 sparingly soluble in cold, but readily in hot, methylated spirit.crystals melt at 56'. The The fused crystals exhibit no flnorescence. On analysis, the iollowing results were obtained. I. 0.2165 gave 0.5054 CO, and 0,1052 H20. C = 6i3.65 ; H = 5.40. 11. 0.2012 ,, 0.4692 ,, ,, 0.1002 ,, C = 63-60; H = 5.53. C22H,,0, requires C = 63.77 ; H = 5.31 per cent. The following density determinations of tbe methylic orthoditoluyl- tartrate were made. d 7Oo/4O = 1.1803. d 1OO0/4O = 1.1516. From which can be calculated d 12'14' = 1.2354. d 54.5'/4' = 1.1950. d 13S0/4' = 1.1174. These densities enabled the specific rotation [ z ] ~ t o be calculated for all these temperatures at which the rotation was observed ; the length of the polarimeter tube was in each case 44 mm. Rotation of Methytic OrthoditoluyItaih.nte.-42.30" - [aID a t 12" = - -77.82" 3 , 19 = -42'410 = -78.42 0.44 x 1.2354 0.44 x 1.2291 0.44 x 1.215% 0.44 x 1.1950 - - 7 7.00 -41.17" - ,, 33.5 = ,, 54.5 = - 74.23 -39.03' - -37.40' - 9 70 =--- 0.44 1.1~0;3 - -72.02 -3447" - -34.555" - -30.13" - ,, 100 = - -68.03 0.44 x 1.1516 0.44 x 1.1516 -- 0-44 x 1.1174 0.44 x 1.1162 - 0.44 x 1.0723 - - 68.20 ,. 100 = , 136 = - -61.28 -30.32' - -61.74 ,, 137 = ,, 283 = - - 52.76 - 24.89" N&.-The determinations " I " were made in one series and a t one time; those marked " 11 " were made several months later to check the previous results.1314 FRANKLAND AND WHARTON : Ethylic Paraditoluyltartrate. The method of preparation was the same as that already described above. Forty-five grams Gf paratdupl chloride and 15 grams of ethylic tartrate were employed, 30 grams of criide product passing over at about 280' (7 mm.pressure) being obtained. When cold, it solidified completely ; it was dissolved in hot methylated spirit, from which i t crystallised in beautiful, large, and long prismatic needles somewhat resembling the crystals of ammonium nitrate. After recrystallisa- tion, the finall melting point was found to be 92-93'. On analysis, the following results were obtained. I. 0.2025 gave 0.4820 CO, and 0.1096 H,O. C = 64.92 ; E = 6.0;. 11. 0.2065 ,, 0.4909 ,, ,, 0.1109 ,) C = 64-83 ; H = 5.97. C2cH2,0, requires C = 65-16 ; H = 5.88 per cent, The following density determinations of the ethylic paraditoluy 1- tartrate were made. a io00/40 = 1.0972. J i3so/4o = 1.0688. From which, by extrapolation, d 183*5'/4' = 1.0308, d 137'14' = 1.0680 were calculated.The specific rotations for the same temperatures may be calculated from the observed rotations determined with a tube of 44 mm. length as follows. Rotation of Ethylic Paraditoluyltartrate. -43-44O - - -89.98". 0-44 x 1-0972 [aID at 100' = -38.28' - 3 7 - -81.46. 0.44 x 1.0680 137 = -31.52' - ,, 1fi3.5 = - -69.50. 0.44 x 1.0308 The influence of temperature on the rotation is graphically exhibited in the diagram on p. 1316. As already mentioned, this substance has been prepared by Freundler, who obtained it somewhat differently, namely, by the etherification of diparntoluyltartaric anhydride with alcohol and hydrochloric acid. The melting point of his product, 92-93", is identical with that of ours, and the figures which he gives for its rotation in alcoholic solution are Temp.= 16O, length of tube = 400 mm., concentration = 0.8694, observed rotation CZD = -3" 6', [alD = -83.1".POS1TION-ISO~lERISM AND OPTICAL ACTIVITY. 1315 To compare the rotation of our substance with that of his, we have Temp. = 15*5', length of tube = 198.4 mm., concentration = 0.8676, observed rotation UD = -1*627", [aID = -994.52'. The result is thus somewhat higher, but the difference is incon- siderable when it is borne in mind with what an extremely dilute solution the observation had to be made, any difference being thus enormously multiplied. made the following determination in alcoholic solution, Nethylic Paraditoluyltartrate. This was similarly prepared, and was obtained in the first instance a s a viscid, fluorescent liquid, which rapidly set to a crystalline mass.It was repeatedly crystallised from methylated spirit, The crystals, which are slender needles arranged in radiating tufts, melt nt 88.5'. On analysis, the following results were obtained. I. 0.2170 gave 0.5050 CO, and 0.1059 H,O. C = 63.46 ; H = 5.42. 11. 0.1999 ,, 0.4638 ,, ,, 0.0991 ,, C = 63.28; H = 5.51. 111. 0.2106 ,, 0.4917 ,, ,, 0.1022 ,, C = 63.68 ; H = 5.39. C2&,,0, requires C = 63.7'7; H = 5.31 per cent. The following density determinations were made with this methylic yaraditolu yltartrate. From which by extrapolation the density at 183' was calculated as a io00/40 = 1-1399. a i830/40 = 1.0687. ti 13So/4O = 1.1091. a 135.50/40 = 1.1095.At these temperatures, loo", 136", and 183", the rotation was also observed, and from these data the specific rotations can be calculated as follows :- Rotatioit of Methylic Paraditoluyltartrate. -51.57" - ID at l'Oo = 0.44 1.1399 - -102.82'. -444.68' - 3, - -91.52. 0.44 x 1.1095 0-44 x 1.0687 135.5 = 188 = --56*160 = -76.90, 7 ) After the rotation had been observed a t 183' it was again taken at looo to see whether it had been altered by raising it to this high temperature, but no change whatever was found to have taken place. VOL. LXIX. 4 TE4 Ci; l-3 &z InfEuence of Temperature on the Specific Rotation of Methylic and Ethylic Ditoluyltartrates. Temperature in centigrade degrees. 20" 60" 80" 100' 120" 14Q" 160" 180' 110" I 100' 1 90" ~n U tl II 80" I I TO0 ~ 60" ~ 50" )"POSITION-TSOXERISBf AND OPTICAL ACTIVITY.13 17 Temp. = 16", length of tube = 400 mm., concentration = 0.8660, The rotation of our specimen of methylic paraditoluyltartrate i n Temp. = 15*5', 1engt.h of tube = 198.4 mm., concentration = 0.8679, thus the difference in the rotation of the two preparations is incon- siderable, when the extreme dilution of the solutions examined is borne in mind. observed rotation UD = -3' 46, [ a ] D = -108.7". alcoholic solution was observed rotation aD = -1.931°, [ u ] D = -112.14'. Eihy lic Metaditch y ltart rate. This was prepared in the same way as already described for the previous compounds. Fourteen grams of ethylic tartrate were run drop by drop into 42 grams of metatoluyl chloride heated to 120°, the temperature being gradually raised to 180'.After distilling off the excess of meta- toluyl chloride, the crude product passed over at 279-283' (6 mm. pressure). I t was further purified by washing it in ethereal solution with sodium carbonate, as described for ethylic orthoditolngltartrate. and like the latter it was highly viscous, could not be crystallised from auy solvent, and i t exhibited the same yellowish-green fluoracence. It was again distilled and washed, without any alteration in its rota- tion taking place, and was then submitted to analysis with the following results. 0.1933 gave 0.4595 CO, and 0.1049 H,O. C = 64.83 ; H = 6.03. 0.1886 ,, 0.4479 ,, ,, 0.1006 ,, C = 64.77 ; H = 5.93. C21H,,08 requires C = 65-16 ; H = 5.SS per cent. The density of the ethylic metaditoluyltartrate was determined at the following temperatures.d lOO0/4" = 1.0967. d 136";4" = 1.0673. From which by extrapolation were obtained the ot,her densities made use of in the calculations for specific rotation given below. Rotation of Ethylic Metaditoluyltartrate. (Length of polarimeter tube i n each case was 4t4 mm.) - - 69.31'. 45-43" -35.10' - 0.44 x 1.1617 - At 20.5' [ a ] D = - -68.87. - ,, 24.5 " - 0.44 x 1.1384FRANKLAND AND WHARTON : -34.54" - A t 50' [sc]D = - -69*00." 0.44 x 1.1376 0-44 x 1.0971 - - -31*08" - -64.38. 9 , 99.5 9 , - -30.76" - - -63.74. - 0.44 x 1.0967 7 9 100 7, - - 58.71. - -27.57" - ;, 136 ,, - 0.44 x 1.0673 - Methylic 3fetadifoluyltartrate. This was prepared, in the same wa,y as the previous compounds, from 14 grams of methylic tartrate and 48 grams of metatolnyl chloride.After distilling off the excess of metatoluyl chloride, the crude product passed over at 283' (about 6 mm. pressure). This, which was a, thick syrupy, fluorescent liquid, was washed in ethereal solution with sodium carbonate, and subsequently crystallised from methylated spirit ; the melting point was 83". On analysis, the following results were obtained. 0.1718 gave 0.3998 CO, and 0.0833 H,O. C = 63.47 ; H = 5-39. 0.1862 ,, 0.4325 ,, ,, O*OSS3 ,, C = 63.34 ; H = 5.27. 0.1878 ,, 0.4375 ,, ,, 0.0918 ,, C = 63.53 ; H = 5.43. C,,H,,O, requires C = 63.77 ; H = 5-31 per cent. With this methylic metaditoluyltartmte, the following density determinations were made. d 100°/4' = 1.1395. d 136"/4O = 1.1090.Prom which by extrapolation is obtained d 183O/4O = 1.0692. The rotation was observed at these temperatures, and from the figures obtained the specific rotations can be calculated. Rotation of Methylic m-Ditolziyltartrate. (Length of polarimeter tube in each case = 44 mm.) -39.62' - [aID at 100" = -- - -79.02". 0.44 x 1.1395 0.44 x 1.1090 -334.44" - ,, 136 s - -70.58. -28.68" - - -60.96. 0.44 x 1.0692 ), 183 = lilfluetice of Ternpemture on the Rotation. That the rotation of the etheral salts of tartaric acid is highly sensitive to temperature has been shown many years ugo b-j- PerkinPOSITIOX-ISOJIERIS~I AiSD OPTICAL ACTIVITT. 13 19 (Trans recent shown ., 1887, 51, 363), investigations of that the rotation and ky Pictet (Thesis, Genera, lSSl), whilst Le Be1 (C'oinpt.iwend., 1894, 118, 916) have of the ethereal salts of some diacidyltartaric acids is hardly affected by temperature. The determinations of the rotatory power which we have made of the diacidyltartrates de- scribed in this paper, however, show that these substances are, a t any rate above certain temperatures, extremely sensitive to heat, as will be seen from the diagram on p. 1316. Thus we have only been able to determine the rotation of the methylic and ethylic para-, and the nzethylic meta-ditoluyltartrates at 100' and upwards, and a t these temperatures the rotation mas highly sensitive. On the other hand, in the case of the met,hylic and ethg!ic ortho-, and the ethylic meta- ditoluyltartrates we have determined the rotatmion from the ordinary temperature upwards, and whilst the rotation raries but little up to about 40°, beyond that temperature it is in all cases very sensitive.In Le Bel's experiments the sensitiveness was only determined at low temperatures, namely, from -223' to +16O, thus Observed rotation. At -23". At + IS". Prop,ylic dipropionyltartrate (length of Methylic divaleryltartrate (length of tube = 100 mm.) ................ +6' 12' + 6' 45'. tube = 50 mm.).. ................ -8" - 8' 50'. Hence, i t is possible that a t higher temperatnres they might have become more sensitive, whilst it is worthy of remark also that the above substances investigated by Le Be1 are Fossessed of a much lower rotatory power than those which we have experimented with, and that the actual increase or decrease in rotation brought about by a given change in temperature may partly depend on the niagni- tude of the substance's absolute rotation.(See also in this connec- tion Percy Frankland and Macgregor, Trans., 1894, 65,769.) I t should be pointed out again that increase of temperature di?ninishes the rotation o€ all these ditoluyltartrates, and i t has simi- larly been shown by one of us (Trans., 1896,67,106) that the rotation of the dibenzoylglycerates is diminished by increase of temperature. Now, in both cases the sign of the rotation is conditioned by the presence of the aromatic groups, for the simple ethereal salts of glyceric acid are laevorotatory, whilst the ethereal salts of dibenzoyl- glyceric acid are dextrorotatory ; again, the simple ethereal salts of tartaric acid are dextrorotatory, whilst the ethereal salts of di- benyoyl- and ditoluyl-tartayic acids are Iaxorotatory.Thus, with rise of temperature the rotatory effect of the aromatic groups diminishes. It would appear, therefore, that with rise of1320 POSITION-ISOMERISM AND OPTICAL ACTIVITY. temperature the rotatory effect of groups containing a closed chain or r i n g does not increase as rapidly as that of a group consisting of an open chain. Thus the alkyl group in the ethereal glycerates tends to produce I~vorotation, in the ethereal tartrates dextrorota- tion, whilst the benzoyl groups in the dibenzoylglycerates tend t o produce dextrorotation, and the benzoyl and toluyl groups in the dibenzoyl- and ditoluyl-tartrates tend t o produce l~vorotation ; with rise of temperature, however, in each case the rotatory effect of the alkyl groups becomes more and more dominant.It is worthy of remark also that in these ditoluyltartrates the rotation of the methylic cGmpounds is more sensitive t o temperature than that of the corresponding ethylic compounds. Very remarkable, again, in this connection is the behaviour of the pheaacetfl groop. The diphenacetylglycerates have a rotation of the same sign (lrevo) as fhe simple glycerates, showing that tmhe aromatic group, when attached to tlie asymmetric carbon atom by means of -CH,*CO- does not dominate over the alkyl group, but rise of temperature causes these diphenace tylglycerztes to become less laevorotatory, showing that in this case with rise of temperature the rotatory effect of the aromatic or ring group makes itself more felt.The rotation of the diphenacetyltartrates (Freundler) similarly has the same sign as that of the simple tartrates, and i t is to be antici- pated that in their case also the rotation will diminish with risc of temperature. Efect of Position-isornekm o r b Rotation. The results obtained with the six componnds which we have prepared and examined show conclusively that the ortho-arrange- ment has the least, and the para-arrangement the greatest, rotatory effect, and that the rotatory effect of the meta-arrangement is inter- mediate between that of the other two, but approximating nearer to that of the ortho- than to that of the para-arrangement. As far as we are aware, there is only one isolated observation bearing on this problem which has been hitherto made. Walden (Zeit. physikal. Chenz., 1895, 17, 2G4) prepared the ortho- and para- ditoluides of malic acid, the rotation of which he determined i n solution only, and with the result t,hat the para- was found to possess a considerably higher rotation than the ortho-compound. This observation, as far as it goes, thus confirms the relationship which we have established in the case of the isomeric etthylic and methylic ditoluyltartrates. The relative rotatory effects of the ortho-, meta-, and para-arrange- ments is quite i n accordance with M. Guye’s theory that the rotatory power of a group is dependent not only on its mass but also on theTHE CHEMISTRY OF PHENOL DERIVATIVES. 1321 moment of the mass (" bras de levier ',) around the asymmetric carbon atom, for assnming that the cent,re of gravity of the benzene ring is the geometrical centre of a regular hexagon, it is obvious that in the ortho-arrangement of the toluyl group the centre of gravity is somewhat nearer, in the meta,-arrangernent somewhat further, and in the para-arrangement still further than that geometrical centre from the carbon atom by means of which the ring is attached to the asymmetric carbon atom. X a s ,n College, Birnting ham.

ISSN:0368-1645    

DOI:10.1039/CT8966901309

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

THE CHEMISTRY OF PHENOL DERIVATIVES. 1321 LXXXT1I.-Contributions to the Cl~ernistry of Phenol Derivat ires. By RAPHAEL MELDOLA, F.R.S., GEORGE HAROLD WOOLCOTT, and EDWARD WRAT. IN the course of an investigation, having for its object the synthesis of eugenol and other allied natural products by direct methods which should give confirmation of the generally received constitutional formuh of these compounds, we have had occasion to prepare a number of new phenol derivatives, which appear t o us of sufficient interest to form the subject of a communication to the Chemical Society. Although there can be no doubt of the correctness of the formulae generally assigned to eugenol and such related compounds as chavibetol and safrole, no direct syntlietical confirmation of these fcrmulae bas as yet been furnished.In view of the general interest which attaches to the synthesis of natura.1 products by artificial methods, it appeared desirable to make an attempt to supply such confirmation. During the course oE the work, which was comnienced last autumn, the subject has been independently taken up by Moureu, who has succeeded in synthesising methyleugenol (Compt. rend., 1895, 121, 72l), and, more recently, isosafrole (ibid., 1896, 122, 792). On referring to Moureu’s papers it will be seen that the result’s which he has obtained still leave the position of the allyl group an open question, while eugenol itself cannot be obtained by his method, which con- sists in boiling the substituted pyrocatechol (veratrole) w i t h allyl iodide and zinc dust. Tbe methylene-derivative of pyrocatlechol does not appear to yield safrole by this treatment.The most obvious method of arriving a t the products referred to would be through the corresponding halogen derivatives of methyl- and methylene-pyrocatechol by condensation with allyl iodide in the usual way. For this purpose compounds of the following types would be required.1322 XELDOLA, WOOLCOTT, AND WRAT i The first of these corresponds to eugenol, the second to chavibetol, and the third to safrole. Phenol derivatives of these types are, how- ever, at present very imperfectly known. The paranitrosoguaiacol of Best (AnnuZen, 1889, 255, lS4), the methylenenitropyrocatechol of Hesse and Jobst (AnnuZen, 1879, 199, 73), the iiitropyrocatechol of Weselsky and Benedikt of melting point 168' (Monatsh., 7SS2, 3, 386)*, the nitroveratrole of Merck (Annalen, 1858, 108, GO), and Tiemann and Matsmoto (Ber., 1876, 9, 939, and 1878, 11, 131), the benzoylbromoguaiacol (" bromoguaiacol benzoate ") of Kauschke (J. pi-.Chem,., 1895, [S], 51, XO), and the nitroguaiacol of melting point 104' (acetyl derivative, melting point 101-102° ; benzoyl derivrttive, melting point 102-103*) recently described by one o the authors (Proc., 1896, 12, 125) are the only known compoufids which can, with any certainty, be assigned to the above types. The preparation of the haloid derivatives from the last-named nitro- guaiacol will be made the subject of future investigation. In the present paper, we bring together a number of miscellaneous results which have been obtained incidentally, and which have been worked out to a considerable extent by taking advantage of the mateyials and bye-products prepared in the course of the research.The nomenclature of the new compounds described is that adopted by Beilstein in the last edition of tlie Aundbuch. 4- Cl~loro-3-nit~ophenol. The nitroaminophenol obtained from diacetyl-p-aminophenol by nitration and hydrolysis (Hahle, J. pr. Chem., 1891, [2], 43,63) readily gives the above chloro-derivative by heating the diazo-chloride with cuprous chloride according to Sandmeyer's process. The nitroamino- phenol is described by Hahle as having a melting point of 148' (from ether) ; after repeated crystallisation from water we found the melting point to be 149-150°. The successive stages of the hydrolysisof the nitrodiacetylamiuophenol are well marked by changes of colour ; on first dissolving in cold sodium hydroxide solution the monacetjl derivative is at once formed, and dissolves with an orange colour, which changes to a deep reddish-violet after heating for some hours * There must be some error in the published descriptions of this process, as the quantity of potassium nitrite (20 grams for 4 grams of pyrocatechol) is more than six times the quantiky required by theory.An experiment with the proportions indicated gave a most unsatisfactory result.THE CHEMISTRY OF PHENOL DERIVATIVES. 1323 on the wat,er bath, this chaiige indicating the formation of the nitro- aminophenol by the removal of the second acetyl-group. The deacetglation no doubt begins with the acetoxy-group.4-Chloro-3-nitrophenol crystallises from water in long, whitish needles melting a t 126-127'. 0.2645 gave 11.4.7 C.C. moist nitrogen a t 14.5" and 760.2 mm. N = 8.17. C,H,*NO,*Cl.OH requires N F 8-09 per cent. The corresponding chloroaminophenol could not be isolated owing to its extreme iustability, but tlhe benzoyl derivative was readily obtained by the action of beiizojl chloride in the presence of caustic soda solution, and, after crystallisation from alcohol, formed white needles, or (from strong alcohol) scales having a melt,ing point of 0.0940 gave 4.4 C.C. moist nitrogen a t 13.5" and 762.8 mm. N = 5-54. C6H3*CI.0H*NH*C7H50 requires N = 5.66 per cent. The benzoyl and acetjl derivatives of the chloronitrophenol were also prepared, the former by the action of benzoyl chloride in pre- sence of aqueous caustic soda, and the latter by boiling the coinpound with acetic anhydride and dry sodium acetate.Benzoyl derivative : white needles from alcohol ; m. p. 96-97". 0.1160 gave 5 C.C. moist nitrogen a t 17.6' and 770.3 mm. N = 5-06, 191-192'. C6H3C1*N02*OC5HS0 requires N = 5.05 per cent,. Acetyl derivative : white needles from alcohol ; m. p. 83-85'. 0.1008 gave 5.5 C.C. moist nitrogen a t 20' and 769.2 mm. N = 6.24. C6&C1*N0,*OC2&0 requires N = 6.51 per cent. The chloronitrophenol dissolves in aqueous alkaline solutions with a feeble orange colour. By the further action of nitric acid it is converted into a mixture of isomeric chlorodinitrophenols, the sepa- ration of which has not yet been effected for want of material.Derivatives of Orthoaminophemd. The monicetyl derivative, which has already been described (Ladenburg, Bey., 1876, 9, 1524), is easily prepared by boiling the hydrochloride with glacial acetic acid, sodium acetate and the calcu- lated quantity of acetic anhydride. It crystallises from water in silvery scales melting at 202-203' (201' from dilute alcohol ; Ladenburg). If the dry aminophenol hydrochloride is boiled with excess of acetic anhydride and dry sodium acetate for some hours, a diacetyl deriva- tive is formed. This compound crystallises from water in white prismatic needles melting a t 123-124".1324 NELDOLA, WOOLCOTT, AND \FRAT : 0.1485 gave 0.3392 CO, and 0.0804 H,O. 0.1162 ,, C = 62.29 ; H = 6.01.6.9 C.C. inoist nitrogen at. 11.5' and 776.9 mni. N = 7.22. C6H4<ZZ2320 requires C = 62-18 ; H = 5.7 ; N = 7.25 p. c. During the acetylstion of the aminophenol by means of acetic anhydride and sodium acetate, i t was always observed that an intense violet colour was a t fii-st produced ; this probably arises from the oxidising act,ion of a trace of acetic peroxide present in the anhy- dride. Other oxidising agents give the same colouring matter. I t is of iriterest to note also that on one occasion we obtained a hydrated diacetyl derivative melting a t 76-77", and crystallising in long, white needles. Analysis indicated the formula but the conditions under which this hydrate is formed require further investigation. ( 2 - ace tami n oph enol) combines readily with diazo-salts in the presence of alkali.As one representative of the class, the compound from metani trodiazoben- zene was prepared and examined. 'It was prepared by adding a solution of diazotised metanit8raniline to a solution of the acetamino- phenol in sodium hydroxide, keeping the alkali in excess thiaoughout. The azo-compound separates as an ochreous gelatinous precipitate on acidifying, and was obtained pure only after crystallisation from nlcohol, glacial acetic acid, and aniline i n succession. It consists of small, ochreous scales, having a melting point of 251-252O, and a t the same time decomposing. It dissolves in alkaline solutions with an orange colour, and is reprccipitated by acids as an ochreous jelly, which becomes slowly crystalline on standing ; strong sulphuric acid dissolves it with an orange colour, which becomes somewhat redder on adding water.0.1016 gave 16.1 C.C. moist nitrogen a t 17' and 767.3 mni. N = 18.43. NO2*CcH~*K,*CcH3~OH~NH*C,H,O rcquires N = 18.6 per cent. Azo- deriztatives.-Th e monace tyl derivative The azo-compound has no doubt the constitution Its phenolic character is shown not only by its solubility in aqueous alkali, but also by the formation of a dull red sodium salt which is stable only in the presence of excess of alkali. An attempt to remove the acetjl group by the action of ricids and alkalis gave unsatisfactoi.y results, as hydrolysis takes place with greatTHE CHEMISTRY OF PHENOL DERIVATIVES. 1325 difficulty. A small quantity of a basic azo-compound (metnnitro- benzene-4-azo-2-aminopheaol) was obtained ; this consisted of small, brown scales, decomposing at about 170°, and soluble in alkaline solutions with an orange colour.A further stndy of this compound will be undertaken with a larger quantity of material, as it will be of interest to ascertain whether it is possible to arrive a t an azo- derivative of pyrocatechol through this source. Niitro-derimtices.-Diacetyl-o-aminophenol is readily nitrated by dissolving in cold nitric acid (1.42 sp. gr.), adding a small quantity of fuming acid, and allowing the solution, kept well cooled, to stand for about three hours. The nitrodiacetyl derivative can be crystal- lised from boiling water, and consists of small, whitish needles, melting a t 187": and beginning to shrink about 182".0.0836 gave 8-15 C.C. moist nitrogen a t 12.75Oand 784.2 rnm. N = 11.86. CsHs'NO2*0C2H30.NH.C~~~0 requires N = 11-76 per cent. The nitro-compound clissolres at once in cold sodium hydroxide solution with the loss of one acetyl group and the formation of a n orange solution. If the caustic alkali is strong, a sodium salt sepa- rates out in red crystals. The second acetyl group is removed o n boiling for a few minutes, and a deep orange-red solution is obtained, from which, on ueutralisation (preferably with acetic acid), the nitronminophenol separates out on cooling in the form of long, orange needles, melting at 201-202'. This compound is identical with the 5-nit~o-2-aminophenol of Friedlander and Zeitlin (Bsr., 1894, 27,196), the identity being established by comparison with a specimen prepared by the method of the authors referred to, viz., heating paranitrophenylaaoimide with dilute sulphuric acid.The nitro- group is thus proved to enter the para-position with respect to the acetamino-group. OAc OAc OH i'rH*Ac \/ ' If the nitration of the diacetyl derivative proceeds too far, a dinitro-compound is obtained which, on hydrolysis, furnishes a dinitroaminophenol, melting a t about 147". This may possibly be the unknown 4 : 5-dinitro-2-aminopheno1, but the compound was only obtained in small quantity and requires further investigation. 2- Chloro- 5-nitrophenol. The above nitroaminophenol, when dissolved in dilute hydrochloric acid and treated with the necessary quantit,y of sodium nitrite, at132 (i MELDOLA, WOOLCOTT, AND WRAT : once forms a red, crystalline diazoxide, which separates from t\Je solution if the latter is not too dilute.On heatirg with cuprons chloride, the corresponding chloronitrophenol is obtained. The latter crystallises from hot water in white needles, melting at 118-119". The beiizoyl deri-rative, prepwed in the usual war, crystallises from alcohol in white needles, melting a t 127-l2tr0. This chloronitrophenol is probably identical with that ob tairied by Schlieper (Be?.., 1893, 26, 2466) by the chlorination of inetanitro- phenol, and of which the melting point is given as 120'. We did not observe, however, that our compound offered any special difficulty with respect t o its power of crystallising from water (compaw Schlieper, Zoc. cit.).Should the identity of the compounds bc established, the constitution of Schlieper'e chloronitrophenol will thus be proved, and the formula to which that author gives the preference will require modification. 2-13romo-4-?aitro-6-anziico~heiaol. When phenol, dissolved in glacial acetic acid, is mixed with one moleciilar proportion of bromine dissolved in the! same solvent, ti mixture of ortho- and para-bromophenol is obtained. An attempt to nitrate this mixture by dissolving in cold nitric acid (1.42 sp. gr.) with the object of obtaining a supply of 4- bromo-d-nitrophenol showed that tohe orthobromophenol is attacked in preference to the para-compound, and a good yield of 2-bromo-4 : 6-dinitrophenol of Laurent, Korner, &c., m. p. 118-119', was obtained. This com- pound is easily purified by taking advantage of the insoliibility of tlhe ammonium salt, which can be crystallisqd from water till a specimen of the free compound (liberated by dilute sulphuric acid and crystallised from alcohol) has the right melting point. When heated for some hours with excess of ammoniiim sulphide solution, the compound is reduced, and on neutralisation with acid, the bromo- nitroaminophenol is precipitated in the crystalline form.It consists of whitish needles, which become brown when dry ; it is soluble in boiling water, and is best purified by crystallisation from this solvent. The compound is both basic and phenolic, the alkaline solutions being of a deep brownish-red, and possessing considerable tinctoyial power. The melting point is 162-163".0,0820 gave 8.35 C.C. moist nitrogen a t 11.5' and 745.5 mm. N = 11.86. C6H2*Br*N02*NH2*OH requires N = 12.01 per cent. AcetyZ Derivative.-Formed by acetylating in acetic acid solution with acetic anhydride. Small, white needles (from boiling water), melting with decomposition at 194" if heated slowly, or 204O if heated rapidly.THE CHEJIISTRT OF PHENOL DERIVATIVES. 1327 0.0788 gave 6.7 C.C. moist nitrogen a t 11.5 and 752.7 mm. N = 10.0. C6H2Br.N02*OH-NH*CzH,0 requires N = 10.1 per cent. Anhydride ~f Acetyl Derivative.-Prepared by b d i n g the mon- ncetyl derivative with acetic anhydride and dry sodium acetate. Crystallisecl from glacial acetic: acid it consists of small, white needles, melting at 146-147'. 0.1150 gave 10.3 C.C. moist nitrogen a t 12' and 768 mm.N = 10.64. N C,H,Br~N02<O>C*CH3 reqnires N = 10.89 per cent. JIethyl-ethe?- =: Bromoiaitro-o-anisidilze.-The monacetyl derivative above described can be methylated, although very imperfectly, by cohobating with the calculated quantities of potassium hydroxide and methyl iodide in methyl alcohoJic solution. After distilling off the alcohol, and removing the utinltered subst,ance by diliite alkali, the methyl ether remains as a yellowish residue which, after hydro- lysis by boiling with sodium hydroxide ancl precipitation by acid, crystallises from hot water in the form of yellow needles, melting a t 120-121'. The yield is small, as the greater portion of the com- pound escapes methylation. 0.0810 gave 8 C.C. moist nitrogen at 19' and 773.4 mm.N = 11.55. CGH2*Br*N02*NH2*OCH3 requires N = 11.33 per cent. An attempt to prepanre this compound by first methylating the bromodinitrophenol and then partially reducing, failed, owing to the impossibility of methylating the latter compound by the action of methjl iodide on the potassium salt under ordinary conditions. We mention this negative result as another illustration of the difficulty of etherifying compounds containing hydroxyl (or carboxyl) between two ortho-substituents, as the subject is now undergoing investigation by Victor Meyer and others. Diazoxide.-On adding a solution of sodium nitrite to a solution of the hydrochloride of bromonitroaminophenoI, a yellow diazoxide, crystallising from hot water in needles, is a t once precipitated. This compound has a decomposing point of 152-153'.0.1328 gave 18.4 C.C. moist nitrogen a t 9.5'and 777.9 mm. N = 17.02. C2H2Br*N02<2> requires N = 17.2 per cent. The diazoxide is stable towards boiling water and cuprous bromide, but gradually decomposes and becomes brown on exposure to light. The constitution of the preceding compounds is shown in the fol- lowing formulae.1328 MNLDOLA, WOOLCOTT, AND WRAP : \/ XO., '\/ NO, \/ NO1 OCU3 N-0 $/\& I ! \/ NO.) NHf?r \/ ' NO, 2- Chloro-4-Nitrophenol. This compound has been previously described by various chemists (Armstrong, this Journal, 1872, 25, 14; Faust and Muller, Annalen, 1874, 173, 309 ; Faust, Zeit. f. Chem., 1871, 339 ; Kollrepp, Annulen, 1886, 234, 4).-We have only to add t'hat it is readily obtained from 4-nitro-2-aminophenol (Laurent and Gerhardt, Annulen, 1850, 75, 68) hy Sandmeyer's process.The benzoyl and acetyl derivatives were prepared in order to characterise the compound more fully :- 0.1011 gave 4.4 C.C. moist nitrogen at 19" and 765.7 min. Benzoyl Deriz,atiz.e.-White silky needles from alcohol ; m.p. 135". CsH3*C1*N02*OC7H50 requires N = 5.05 per cent. N = 5.05. Acetyl Dericative.-White needles froin dilute alcohol ; m.p. 63", but softening before this temperature is reached. 0.1072 gave 6.15 C.C. moist nitrogen at 20.8" and 758.1 mm. N = 6.50. C,H3Cl*NO2*0C~H3O requires N = 6.50 per cent. It is to be observed that on diazotising the 4-nitro-2-arninophenol with a view to replacing NH, by C1, by Sandmeyer's method, a diazoxide is first formed as a yellow precipita,te,* and this decom- poses at owe when mixed with the cuprous chloride solution.The acetyl derivative is readily converted i n to a dinitro-derivative by dissolving in ordinary 1.42 sp. gr. nitric acid, adding a little fuming acid and allowing to stand in the cold for two hours. The product, after hydrolysis by sodium hydroxide, proved to be the 2-chloro-4 : 6- dinit.ropheno1 of Griess, and others (Annulen,, 1859,109, 296). The melting point of a specimen crystallised from water was 111-112". On reduction with ammonium sulphide it gave the 2-chloro-4-nitro- 6-aminophenol of Griess ; m. p. 160" (ibid.: 291). This diazoxide decomposes on boiling with water, giving rise to a reddish It is uncrystallieable, phenolic colouring-matter, which is not nitropyrocatechol and possibly related to the oxazines.THE CHEMISTRY OF PHENOL DERIVATIVES.?329 Derit-atives of Anisole. 4- B.romo-S-nitroaniso~e is most conveniently prepared by bromina t- ing orttionitrophenol in glacial ace& acid, purifying the product by crystallisation from the same solvent, and laethylating by the action of methyl iodide on the dver-salt. The acetic acid mother liquor contains some 4 : 6-dibromo-2-nitrophenol of M. p. 117-118* The bromonitroanisole has all the properties ascribed by its discoverer {Staedel, Aiznalen, 1883, 217, 55 ; Ber., 1878, 11, 1750). The direct bromination and subsequent nitration of anisole in acetic acid solution gives rise to a mixture of 2-bromo-4-nitro- and 4-bromo-%nitro- anisole which cannot conveniently be separated into its components.4-Bromo-2-aminoanisole = Bromanisidine.-T he reduction of the bromonitroanisole was studied under various conditions. With zinc: dust in acetic acid solution, a colouring matter is produced at the first stage, and much resinous matter is always present at the end of the process ; the yield of bromoaminoanisole in not good. With tin and hydrochloric acid the yield of bromoaminoanisole is betier and the base was found to possess the m. p. (97-98') and other properties as described by Staedel (Annulen, 1883, 217, 59). It appears, how- ever, to have escaped notice by previous investigators that reduction with tin and hjdrochloric acid gives rise also to the formation of a small quantitjy of a base, probably of the lnenzidine or semi-benzidine series.This base remains in the aqueous solution after the bromoamino- anisole has been allowed to crystallise out by neutralisation of the acid solution with ammonia. It consists of whits needles decom- posing at about 135'. We have not been able to convert the bromoaminoanisole into bromoguztiacol by the diazo-reaction, or any modification thereof. The diazo-sulphate when boiled with water or dilute sulphuric acid, or the amino-compound itself treated with sodium nitrite in warm, glacial acetic acid is converted into a resinous, nncrystallisable colouring matter containing about 4 per cent. of nitrogen and non- phenolic in character. This resinous colonriug matter is possibly related to the oxazines, but further investigation is necessary before any definite notion concerning its nature can be formed.4-Nifro-2-aminoanis~le = Nitroanisidine.-This compound was pre- pared by reducing 2 : 4-dinitroanisole with alcoholic ammonium1330 NELDOLA, WOOLCOTT, AND WRAY : sulphide (Cahours, Annnlen, 1850, 74, 301). As it was probably described from a n impure preparation by its cliscoTerer, who states that it consists of garnet-red needles, we give some further charac- teristics. When crystallised from boiling water, i t forms orange needles melting at 118'. 0.1192 gave 1 7 C.C. moist nitrogen at 12.5°nnd 733.1 mm. N = 16.27. CGH3-NOz*NHa*OCH3 requires N = 16.66 per cent. The acetjl derivative, CsH3*NO2*NH(C2H3O)*0CH3, consists of white needles melting at 174-175" ; it is soluble in boiling water and was crystallised from this solvent.The base, when diazotised in dilute sulphuric acid and boiled with water, is converted info a reddish phenolic colouring matter which could not be crystallised ; no nitroguaiacol is formed. When diazotised in glacial acetic acid, crystalline products are formed of which the investigation is not yet complete. We may add that the 2 : 4-dinitroanisole used for the preparation of the nitroamino-compound was prepared by the following modification of the original method of Cahouys (Annulen, 1849, 69, 236).-Forty grams of anisole are mixed with 40 C.C. of strong sulphuric acid and the mixture heated on the water bath for a few minutes till a drop withdrawn and mixed with water i n a, watch-glass dissolves to a clear solution without opalescence.The contents of the flask are then cooled and 40 C.C. of fuming nitric acid mixed with an equal volume of strong sulphuric acid are run into the solution in a thin stream with frequer?t agitation. The solution must not be allowed to get perceptibly warm during the process; i f any tendency to over heating is observed at first, the stream of nitrosulphnric acid must be stopped. The mixing of the solutions takes about two hours, and the nitration may be completed at the end of this operation by warming gently on a water bath. On stirring into cold water and allowing to stand, the dinitroanisole separates out in a crystalline form. 5-~itr0-2-aminoanisoZe.-The acetyl derivative of this compound was prepared by Miihlhauser (AnnuZen, 1881,207,242) by nitrating ortho- acetaniside.The corresponding nitrortminoanisole can be obtained by boiling the acetyl derivative for a few minutes with dilute sodium llydroxide solution, and then heating for some hours on a water- bath to complete the hydrolysis. The compound separates on cooling in the crystalline form and after crystallisation from hot water, consists of yellow needles melting at 139-140'. (j.0888 gave 12.7 C.C. moist nitrogen at 15.5Oand 758.7 mm. N = 16.64. CEH3*NO2*OCH3*NH2 requires N = 16.66 per cent.THE CBE3IISTBY OF PHESOL DERIVATIlTES. 1331 The acetyl derivative melts at 145-246' ( 1 4 3 O , Nuhlhauser) after The nitroaminoanisole was not repeated crystallisation from water. capable of being converted in to nitroguaiacol by the diazo-reaction. Dewhatices of Guaiacol.Mononitro-derivatives of guaiacol have already been described by one of the authors (Proe., 1896, 12, 125). In the course of these experiments a quantity of acetylguaiacol was inadvertently ovey nitrated, and a supply of dinitroguaiacol thus obtained. The com- pound is best prepared by allowing an excess of fuming nitric acid, diluted with glacial acetic acid, to act for some hours on acetyl- guaiacol dissolved in the same solvent, the solution being kept cool by melting ice. The contents of the flask solidify to a crystalline pulp of the dinitro-compound, and the latter can be purified by crystallisa- tion from water. It appears to be identical with the modification obtained by Herzig by passing nitrous gas into a cold ethereal solu- tion of guaiacol (Monatslz., 1882, 3, 825), although our melting point was a little lower (121' instead of 122-123').Nitroumiizoguaiacol .-This compound is readily obtained by heat- ing the dinitroguaiacol for some hours with ammonia and ammonium sulphide. After boiling off the excess of ammonia, the solution is acidified with hydrochloric acid, filtered to remove sulphur, and the nitroaminoguaiacd precipitated by neutralisation with ammonium carbonate. After crystallisation from water, it consists of brown needles with a brilliant lustre melting Fith decomposition at 182'. 0.1624 gave 20.9 C.C. moist nitrogen a t 16' and $69.7 mm. N=15.21. C6H2*N02*NH,*OCH3*OH requires N = 15.22 per cent. NitroucetamiizoguaincoZ.-Pi~ep~red from the pyeceding compound by the action of acetic anhydride in acetic acid solution.Crystallised from hot water, it consists of whitish needles which dissolve in dilute alkaline solutions with an orange colour. At about 170-180° the whitish crystals become coloured of an ochreous-yellow, and at 224-226' decomposition occurs with considerable frothing. The cornpoulld coutains water of crystallisation, which cannot be expelled by heat without the decomposition of the substance, 0.0688 gave 6.8 C.C. moist nitrogen at 18.5'and 758-8 mm. N=ll*35. C6H2*N02*OH*OCH3*NH*C2H30 + H20 requires N = 11-97 per cent. Diacetyl Derivative.-When the monacetyl derivative above de- scribed is boiled for some hours with acetic anhydride and dry sodiiim acetate, a considerable quantity of some bright red, resinous colour- ing matter is formed, together with a white, crystalline substance 0.0714 ,, '7.1 C.C. 9 , 16.5' and 759.5 mm.N=ll-43. VOL. LXIX. 4T.r1332 31ELDOL-4, WOOLCOTT, AND KRAY : which can be rcmoved by extraction with boiling water. After crys. tallisation from boiling water, with the addition of animal charcoal, it consists of white, silky needles which decompose with much frothing a t about 204". 0.0158 gave 1.5 C.C. moist nitrogen a t 24' and 762 mm. K = 10.68. The diace ty 1 derivative, CsH2*N02*0 C2B30*0 CH3*NH*C2H30, requires N = 10.44 per cent. Dinzoxide.-When tt solution of t.he nitroaminoguaiacol in dilute hydrochloric acid is mixed with a solution containing 1 molecular proportion of sodium nitrite, an immediate precipitation of 5t yellow, crystalline diazoxide takes place.Recr-ystallised from dilute alcohol, i t consists of orange needles which explode with a sharp detona- tion a t 169-170". 0,0490 gave 8.6 C.C. moist nitrogen a t 17' and 765.5 mm. N= 20.25. C,H2*N02*OCH3<2> require8 N = 21.53 per cent. This formula + kH,O requires N = 20.58 per ceut. The formation of this diazoxide may be taken as eridence t h a t the amino-group is ortho- with respect to the hydroxyl group, since diazoxides do not appear to be formed from phenolic compounds, unless they possess this constitution. The fact t h a t one of the iiitro-groups is so easily reducible by ammonium sulphidc may be regarded as additional evidence in the same direction, since this reducibility is eminently characteristic of polynitro-derivatives of phenol with a nitro-group in the ortho-position with respect to the hydroxyl group.In view of this evidence we are disposed to assign constitutional formula to these compounds, as shown below, in preference to that given for the dinitroguaiacol in the last edition of Beilstein (rol. ii, 911 : 4, 5-dinitrog~aiacol).~ OH OH X-0 ,UO,/\OCH, NH/\OCH~ rlf /\ OCHs 1 1 ' I 1 \/ \/ NO2 NO, NO2 (1). (11) - (111). l l ' \/ I. 4 : 6-dinitrogusiacol. 11. 4-nitro-6-aminoguaiacol. 111. 4-nitro-6 : 1-diazoxy-2-anisole. * There is some ambiguity about the constitution of this compoi.nd as expressed by the abore nomenclature. The notation usrd applies equallj well to- (I). C~H,.OCH3*NO2*NO,*OH = 1 : 4 : 5 : 6. (11). C,jH~.OH*IV02.NO~.OCH3 = 1 : 4 : 5 : 6. The eecond of t,hese is excluded for the reasons assigned, viz., the formation of aTHE CHEMISTRY OF PHESOL DERIVATIVES.1333 2liZetnnitrobenzeneazogunincol (benzoyl derivative) .-This compound was prepared with the object of ascertaining whether the azo- derivatives of benzoylguaiacol cou Id be conveniently reduced so as to furnish benzoylaminoguaiacol. The result was not satisfactory ; but, as the compound has not hitherto been described, we give the following account. Diazotised metanitraniline (in hydrochloric acid solution) is allowed to flow into an ice-cold alkaline solution of guaiacol, the liquid being kept alkaline throughout. A deep red colour is developed, and, after filtration to remove a small quantity of some insoluble product,* the azo-compound is precipitated by acid, and is obtained as a resinous, uncrystallisable, ochreous substance soluble in alkali, with a red colour, and readily converted into a benzoyl derivative by agitating the alkaline solution with beiizoyl chloride.The benzoyl derivative was crystallised repeatedly, first from alcohol, i n which it is but very sparingly soluble, and, finally, from glacial acetic acid. It was thus obtained in the fmm of brown, warty nodules melting at 135-136'. 0.1168 gave 10.9 C.C. moist nitrogen at 13" and 769.4 mm. N = 11.13. N02*C6H4*N2-C6H3.0CH3*OC7H50 requires N = 11.14 per cent. The azo-group is, no doubt, in the para-position with respect to the hydroxyl, and the formula of the original compound may be written OH 00CH3 NgCBH~.NO,(~n). Nothing definite was obtained by the reduction of this azo-corn- pound, and its further investigation was, therefore, discontinued.Dericniives of Pyrocatechol. By nitrating the diacetyl derivative of pyrocatechol, Nietzki and Moll obtained a dinitropyrocatechol melting at 164", which these authors regard as 3 : 5-dinitropyrocatechol (Bey., 1894,26, 2183). We do not consider the evidence in favour of this constitution as conclusive, but, accepting this view provisionally, it seemed of interest to apply the tests of the reducibility of one nitro group and the formation of a diazoxide in order to ascertain whether the compound contained a nitro-group in the ortho-position with respect to hydroxyl. The diazoxide from the corresponding nitroamino-derivative. Even with this alterna- tive interpretation, however, the formuIa suggested by us appears more probable than (I). Further experiments will be undertaken with the object of deciding whether the nitro-groups are ortho with respect to each other. * Pozsibly an ortho-azo-comporincl, such compounds being non-phenolic, and therefore insoluble in the alkaline solution. 4 u 21334 WALKER ASD APPLEYARD : evidence in favour of this point is conclusive, but the constitutionnl formula is not thereby proved, sirice the 4 : 6-dinitropyrocatechol (or tlie 5 : 6-modification) might be expected to yicld a similar result. 5-h~it~o-3-ami.itopy~ocatechot is readily obtained by reducing the dinitro-compound with ammonium sutphide in the usual way. The substance is distinctly basic, and, also, strongly phenolic, dissolving in alkalis with a deep orange-brown colour. It is extremely soluble in alcohol, and can be crystallised from boiling water from which i t separates on cooling in the form of flat, ochreous needles having a decomposing point of 220-221’. Dimoxide.-On adding sodium nitrite to a, cold solution of the hydrochloride of the base, the diazoxide separates in the form of flat needles of a beautiful golden-orange colour. The compound explodes with a sharp detonation a t 159-160’ ; it is phenolic in character, and dissolves in dilute alkaline solutions with a purple colour. Although so explosive when heated, it does not explode by percussion. 0.1035 gave 19.9 C.C. moist nitrogen at 21’ and 765.85 mm. N = 22*0$. c,H,*No~*oH<~> + +H,O requires N = 22-10 per cent. The constitutional formuls of these compounds may be written OH orH , OH i’\-O ! lk. N0,1,)NH2 XOJ,/-” I It These formulae a.re based on Nietzki and Moll’s view of the ~011- s ti tu tion of the dinit ropyrocatechol. Finsbury Techibica 1 Col1 ege.

ISSN:0368-1645    

DOI:10.1039/CT8966901321

出版商:RSC    

年代:1896

数据来源: RSC

摘要:

1334 WALKER ASD APPLEYARD : LXXX1V.-Absorption of Dilute Acids by Silk. By JAMES WALKER, D.Sc., Ph.D., Professor of Chemistry, and JAnfed R. APPLETARD, F.C.S., Lecturer on Dyeing, University College, Dundee. PRIOR to 1890 there existed two theories as to the nature of the process of dyeing-the chemical and the mechanical. They were, however, felt to be unsatisfactory, for neither could claim to give a f u l l explanation of the phenomena. When Witt, therefore, in the year named, put forward the suggestion that the state of the dye in the fibre is analogous to that of a substance in solution, the investigation of the problem received a new direction and a freshABSORPTION O F IjJLUTE AClDS BY SILK. 1335 impulse. The hypothesis that the dyed fibre is a solid solution of tlie dye is, as it were, intermediate between the two earlier theories, and t o a certain extent combines the adrantages of both.Witt adduced in its support (Fiirbe)*zeitung, 1890-91, 1 ; Jozcr. SOC. Dyws and Colourisfs, 1890, 6, 173) a great number of' instances derived from special experiments, and from the general experience of prac- tical dyers. Dyes, for example, which have a different colour i n the solid state from that which they hare in solution, confer on the fibre the colour of the solution and not that of the solid. Again, materials are known to exhibit marked fluorescence when coloured with dyes which are not themselves fluorescent, but yield fluorescent solutions. The actual process of dyeing with substantive colours mas likened to the extraction of such a substance as resorcinol from its aqueous solution by agitation with ether. The solvents, water and ether, share the resorcinol between them; similarly, the dye is shared by the fibre and the water of the dye-bath.These and other examples of like nature showed at least a super- ficial resemblance between the state of a dye in the fibre and of a substance in solution ; but much more experimental evidence was required before the solid solution theory could be accepted. We know at the present day mith a high degree of accuracy the laws regulating solutions, and in particular from the work of Nernst the laws of distribution of a substance between two immiscible solvents ; so, if the dye is really dissolved in the fibre, we should expect it to obey these laws.When the molecular complexity of the dissolved substance is the same in both solvents, it so distributes itself between them that a t any given temperature there is a definite ratio between the concen- trations of the two solutions when equilibrium is attained, the ratio being independent of the amounts of substance and solvents origin- ally taken. Thus iodine, when shaken up with carbon tetrachloride and water, is shared by these solvents in such a way that the con- centration of the aqueous solution produced is to that of the carbon tetrachloride solution as 1 to 85, that being approximately the ratio of the solubilities of iodine in the two solvents at 25", the tempera- ture of experiment (Jakowkin, Zeit. physiknl. Chena., 1895, 18, 588). When the molecular complexity of the dissolved substance is not identical in the two solvents, there is no constant ratio of distribu- tion, the ratio of the concentrations varying with the original quan- tities present.There is, however, in such cases a somewhat more complex function which takes the place of the simple distribution ratio. If the molecular weight of the substance in one solvent is n times as great as its molecular weight in the other- solvent, then, when equilibrium is attained, the nth root of the concentration in1336 WALKER AND APPLEYARD : the first solvent will bear a constant ratio to the concentration in the second solvent. These laws should hold good for dyeing if the solid solution theory is correct. When the dye in the dye-bath is in the same molecular condition as the dye in the fibre, there ought to be a con- stant distribution ratio between the water and the fibre.In other words, after the fibre has taken up as much dye from the bath as i t will under the given conditions of temperature, &c., the concentra- tion of the aqueous solution of the dye remaining ought always to bear the same ratio to the concentration of the dye in the silk, no matter whether much or little dye were originally dissolved in the water. With different molecular complexities in the water and in the fibre the following formula should be obeyed. Let C , be the concentration of the dye remaining in the dye-bath, Cf the concen- tration in the fibre, and ?z the ratio of the molecular weight of the substance in the fibre to its molecular weight in water; then /G/cw = const.Experiments have already been made in order to ascertain if such a constant ratio actually exists. Georgevics (Monntsh., 1894, 15, 707) concluded from his experiments on dyeing silk with indigo- carmine that the phenomenon was analogous to solution ; but later (ibid., 1895, 16, 345) he has, i n conjunction with Lowy, arrived at the opposed conclusion that dyeing is analogous to absorption. These observers have found that in general Cfl JC, is approximately constant, where, according to them, x expresses the affinity of the dye for the fibre. G. C. Schmidt (Zeit. physikd Chem., 1894, 15, SO), from his observations on the absorption of picric acid by cellu- lose and of eosine and malachite-green by silk, could obtain no constant, ratio of the form given above. He, also, is of the opinion that dyeing is an absorption phenomenon, the fibre playing much the same part that charcoal does when it is brought into a solution of a substance which it is capable of absorbing.In this paper we communicate the results of some experiments on the absorption of various acids by silk, and, in the first place, we give the numbers we obtained for picric acid, a real substantive dye of simple consti tution. Picric acid and Silk. The silk we employed in the experiments was a bleached fibre which we first treated with very dilute hydrochloric acid, washed, and allowed to remain for several hours in warm soap solution. Thereafter it was washed with successive portions of hot distilled water, until the liquid with which it had been in contact for three hours, was nentral to phenolphthaleYn, and gave no opalescence withABSORPTION OF DILUTE ACIDS BY SILK.1337 silver nitrate. Even after this treatment, the silk left a slight residue on iiicineration, which consisted chiefly of calcium carbonate with a trace of iron. The quantity of ash, however, was not great enough seriously to affect our obserrations, although the numbers for the most dilute solutions we employed are somewhat displaced through its action. The picric acid was estimated volumetrically with potash solution, and at first we experienced some difficulty in finding a suitable indicator for it, the yellow c01ou.r of the solution interfering with the end point shown by most of the ordinary indicators.We finally adopted lacmoid as the most suitable. In daylight, the end point is not sharp, but i n gaslight it is quite definite. We, there- fore, always performed the titrations in a dark corner of the labora- tory, illuminated by a powerful gas jet in the immediate neighbour- hood of the solution. After addition of t.he indicator, the colour is a pale orange, which grows deeper as the alkali is added, and a t the neutral point suddenly strikes into a dirty greenish-brown, further addition of alkali producing a purer green. The neutral point can easily be estimated to EL single drop of a N/20 solution, which was the strength of the alkali we mostly employed. Our method of experiment was to place a weighed quantity of silk and a measured volume of picric acid solution of known strength in an Erlenmeyer flask, which was closed by an indiarubber stopper and immersed in an Ostwald thermostat.After a sufficient time had elapsed, a definite volume of the solution was removed by means of a pipette, and the picric acid in it determined with the standard alkali. A correction for change of volume with the temperature was applied when needful. The first determinations were made by us at looo, a t which tern- peyature the absorption proceeds very mpidly. It was of importance to ascertain if a real limit to the amount absorbed by the silk in any even case was reached, so that we first made a few time experiments. The results of one series are given below. Time of heating. Milligrmis of acid in 1 gmm of silk. 3 hours 64 4. > Y 66 5 7 Y 66 It will be seen that the absorption is practically at an end in three houra, when 1 gram of silk is heated at 100° with 100 C.C.of N/50 picric acid-the proportions used in the above series. Experi- ments with the materials in other proportions yielded similar numbers, so that at looo, 3-4 hours was the length of time given for the substances to attain a state of equilibrium.1388 KLILKER ASD APPLEYARD : It is a necessary conseqnence of the solid eolution theory of dyeing, that if a bath of picric acid is treated with successive quantities of silk, it will finally be completely exhausted ; and, on the other hand, that if silk dyed with picric acid is treated with successive quantities of pure water, all the picric acid will be washed out of the silk.This we found to be true, but as the picric acid is always much more con- centrated in the silk than in the solution which is in equilibrium with the fibre, it is much easier to exhaust the water by silk than to wash out the silk completely with water. A gram of dyed silk has to be boiled 10-12 times with successiT-e portions of 100 C.C. of water before i t is decolorised. Again, if the solid solution theory applies to the case in point, it is a matter of indifference,provided certain amounts of water, silk, and picric acid are git-en, whether the picric acid is originally all in the silk: all in the water, or distributed between these two substances in any ratio whatever. The final equilibrium must always be the same, being determined by a certain ratio of the concentrations in the water and in the silk.If the original concentration in the silk is too great, it mill lose picric acid to the water ; if too small, i t will gain picric acid from the water. We made several experiments with pure water and dyed silk containing a known amount of picric acid. The time for the attainment of equilibrium is here considerably longer than is the case for direct dyeing, at least seven hours being necessary a t 100". 2 grams of silk containing 155 milligrams of picric acid (or 77.5 milli- grams per gram) were heated for seven hours and it quarter at 100" with 75 C.C. of water. The solution at the end of that time was slightly turbid, owing to particles of disintegrated silk fibre held in suspension. Titration with alkali showed the solution to contain 79.6 milligrams of picric acid.I n 1 gram of water there was thus 1-06 milligram of acid, and in 1 gram of silk there remained 37.7 milligrams of acid. Now a direct dyeing experiment showed that silk, when dyed i n it bath containing 1.06 milligram of picric acid per gram of wat'er after the dyeing was complete, took up 36 milligrams per gram. For a given endconcentration in the water, therefore, we arrive at practically the same concentration in the silk, whether the acid was originally all in the water, as iu the dyeing experiment or all i n the silk, its in the boiling-out experiment. Whilst a result such as this is in harmony with the solid solution theory, i t is equally in accordance with any theory which involves equilibrium, whether chemical or physical.In the performance of these preliminary experiments, it was ob- served that the silk became yery tender after heating for n few hours with dilute acid at the boiling point. We therefore conducted theABSORPTIOX OF DILUTE ACIDS BY SILK. 133CI remainder of our observations at GO', at. which temperaturc the siIk is much less affected. A quantity of silk, prepared as indicated above, was air-dried, and cut into pieces weighing 1 gram, the weighed pieces being preserved and used as required. The moisture contained in the silk when it was cut up amounted to 8.4 per cent. I n each experiment, 2 grams of this silk was heated at 60" with 100 C.C. of picric acid of known concentration. The time of heating was 40 hours, special experi- ments having shown that this period was sufficient for equilibrium to be reached.At t'he expiration of that time, the acidity of the solu- tion was estimated by titration. The loss of acidity is not entirely due to the absorption of the dye by the silk, one portion of the acid being neutralised by the ash of the silk, and another, probably much smaller portion, by interaction with the material of the silk, or its decomposition products. I n the following table, the values have been corrected in the manner to be described later, to allow for the neutral- isation by the ash. Milligrams of yicric acid in 1 C.C. of solution. 0.064 0.12 0.59 0.98 1-98 2.93 5-00 7-00 Ililligrama of picric acid in 1 gram of ailk. r--h-- 7 Found. Calculated. 13 13 17 16 27 29 37 35 44 46 54 5:) 64 64 73 r-- / 3 The figures hold good for the composition of the system after the dyeing has been completed, and, in the case of the silk, are referred to the weight of the air-dried fibre.I f we call the concentration in the silk s, and the concentration of the water w, the relation between the first two columns can be fairly well represented by a formula of the type above referred to, namely, s/'T%= 35.5. In the third column are the ralues of s, calculated from this formula. The differences between the observed and calculated num- bers do not fall beyond the limits of the experimental error, and may be better judged b~ an inspection of the accompanying curve (p. 1340), which is that of the above equation. According to the solid solution theory of dyeing, the ralidity of this formula would entail the consequence that the molecule of picric acid in aqueous solution is on the aTerage 2.7 times as great as the1340 WALKER AND APPLEYARD : molecule of picric acid dissolved i n silk.This, however, cannot be the ca~e, for a consideration of the freezing poiit and the electric conductivity of picric acid solutions, indicates t h a t the molecule is not only not greater than is represented by the formula C6H,(N02),*0B, but much less than thie, owing t o the high electrolytic dissociation. 7 G 5 4 .2F 3 2 1 0 0 10 20 30 40 50 60 70 80 The solid solution theory of dyeing, therefore, receives no supp0l.t from the behavionr of silk and picric acid, where the phenomena are comparatively simple. As to the meaning of the formula actually obtained little can be said, but its simple nature may be rendered more evident by a slight mathematical transformation. If we take the natural logarithm of both sides of the equation 'we obtain sI2TW = 35-5, 1 2.7 log s = log 35.5 + r - log 20, which, when differentiated, becomes n s - 1 3w - - .-- s 2.7 a 0 ' In this form the equation states that a slight proportionate change in the concentration of picric acid in the water is always proportional to the corresponding proportionate change in the concentration of theABSORPTION OF DlLUTE ACIDS BY SILK.1361 acid in the silk, Thus, if the coneenti-ation i n the water increases by 1 per cent. of its value, no matter what that value is, the concen- tration in the silk will increase by ~ per cent.of its own value. 1 2.7 Formulae of this kind apply in very many cases of absorption. Poi. instance, it has been shown by Schmidt (Zoc. cit.) that the absorption of iodine and of various acids from their solutions by charcoal can be represented by such a formula, and Kiister (AnnaZen, 1894, 283, 360) has proved that a similai- relation holds good between the con- centrations of iodine in aqueous solutioii and in starch. It does not, of course, follow from the identity of the formula valid in these cases, that the phenomena themselves are identical in nature, but until we are possessed of information to the contrary, there is cer- tainly a presumption in favour of such m supposition. Picric acid and Diphenylamine. In view of the fact that purely chemical theories of dyeing hare been proposed, we thought it of interest to investigate a very simple case of “ chemical dyeing,” in order to compare the results of obser- vation with those predicted by theory.If the union of the dye with the fibre is one of chemical combination, and i f any finite amount of the fibre is incapable of completely exhausting the dye-bath, that is, if there is between the water and the fibre a competition for the dye resulting in equilibrium, the theory of mass action enables us t o predict the nature of that equilibrium. The active masses of the solid fibre, the solid dyed fibre, and of the water remain constant throughout, so that for the action Fibre + (dye, water) = dyed fibre + water, we have the following equilibrium if n represents the active mass of the dye in aqueous solution, that is, its concentration, c x const.x = c‘ x const. x const., c and c’ being the velocity constants of the opposed reactions. FOP equilibrium, therefore, at any given temperature we have the condi- tion n = constant; in other words, the dyed and undyed fibre (these together forming the partially dyed fibre) can only exist in contact with the aqueous solution of the dye when that solution has a certain fixed concentration. The relative proportions of the dyed and undyed fibre to each other and t o the dye have no influence on the equilibrium-for a given temperature there is one, and only one, concentration of the dye-bath with which the dyed fibre can exist unaffected, t h e depth to which it is dyed being of no significance. There is here, then, a great difference from what is found to hold good1342 WALKER AKD APPLETARD : with picric acid and silk, the concentration of the dye bath in that case varying continuously with the depth to which the silk is dyed.As no fibre lrnown to us presented a sufficiently simple and un- doubted chemical union with any dye, we endeavoured to realise the conditions given above with diphenylamine as a substitute. Diphenjl- amine unites directly with picric acid to form a chocolate-brown additive compound, and both this and the arnine are, practically, insoluble in water. Diphenylamine, therefore, represents the pure fibre, and diphenylammonium picrate the fibre dyed to saturation, any mixture of the two corresponding to a partially dyed fibre. When the picrate is treated with water it is partially decomposed, some of the picric acid dissolving and the diphenylamine remaining behind.I€ successive fresh portions of water are used, all the picric acid may be mashed out. At 40.6' the solubility of picric acid in water is 16.8 in 100 parts, 01' the saturated solution contains 16.8 milligrams per gram. Three experiments were made at this temperature, 50 C.C. of saturated picric acid solution being allowed to remain in contact with 2, 1, and 0.5 gram of diphenylamine respectively for 43 hours, with con- stant sha,king. The final concentrations were found to be Milligram8 of picric acid in 1 gram of diphenylamine. Xilligrams of picric acid in 1 gram of water. 13% 7.5 13.7 15.5 13.8 30.0. Again, equivalent proportions of picric acid (2.29 grams) and diphenylamine (1.69 gram) were treated with 50 C.C.water at the same temperature as before. The concentrations were then Milligrams of picric acid in 1 gram of water. Milligrams of picric acid in 1 gram of diphenylamine. 13.9 95. Lastly, 2 grams of diphenylammonium picrate (prepared by fusing together the two constituents in molecular proportions) mere treated with 50 C.C. water. The final concentrations were Milligram8 of picric acid in 1 gram of water. Milligrams of picric acid in 1 gram of diphenylamine. 136 46. These numbers show that .the requirements of the theory are fuI- filled-the concentration of the aqueous solution remains constant, no matter how the proportions of the substances may bc varied, or what their original distribution may have been.If there is not enough picric acid in the system to afford an aqueous solution of this concentration, no solid picrate will be formed, This may beABSORPTIOX OF DILUTE ACIDS BY SILK. 1313 yery readily tested expel-imcntally. A solut,ion of picric acid at $ 0 ~ 6 ~ containing 14 milligrams per C.C. at once stains diphenylamine deep brown, but a solution at the same temperature, containing 13 milli- grams per c.c., leaves the diphenylamine colourless, or only stains i t pale brown after prolonged contact. No case of actual dyeing coryesponds to this-the weakest dye- bath will always colour the fibre, no discontinuity existing at a certain concentration, above which dyeing can take place, and below it Kot. The equilibrium here investigated is the analogue for solutions of such an equilibrium as that between ammonia gas and the compound of calcium chloride with ammonia.For each temperature there is one, and only one, pressure (concentration) of ammonia which is in equilibrium with both calcium chloride and its amrrionia componr_d. If the pressure is less than this, no compound with ammonia can be formed-if i t is maintained at a greater value, no uncombined calcium chloride can exist. InJEueirce of the Solvent. The behaviour of silk towards picric acid in alcoholic solution is not essentially different from the case where water is the solvent. Picric acid is much more soluble in alcohol than in water, and this would lead us to suspect, if there mere any analogy between dyeing and solution, that, for a given concentration in the liquid solvent, less picric acid would be taken from the alcohol than from the water.The results of a few experiments were in accordance with this view. After heating in alcoholic solution for 48 hours at 60' the following :lumbers were obtained for the final concentrations. U. 6. Miliigrams of Milligrams of Milligrama of picric acid in acid in acid in 1 grain of silk. 1 C.C. of alcohol. 1 C.C. of water. a/b. 42.0 6.6 1.6 4.2 28.5 2.9 0.58 5.0 20.5 1-0 0.23 4.4 I n the third column we have added the values for aqueous solutions corresponding to the same concentrations in the silk, by interpolating from the numbers previously given. It is evident that to dye silk to a given standard, the alcoholic solution of picric acid must be con- siderably stronger than the aqueous solution.The ratio of the two concentrations remains fairly constant, and is nearly the ratio of the solubilities of picric acid in alcohol and in water at 60°, namely, 5.0. On investigating benzene as a solvent for picric acid, we found that silk was unable to extract picric acid from benzene solution. At first we were inclined to attribute this t o the fact that pic& acid forms a1344 WALKER AND APPLEYARD : Epecies of compound with benzene as with other aromatic hydro- carbons, and concluded that the silk was incapable of absorbing or breaking up this compound ; but on subjecting silk previously dyed with picric acid to treatment with benzene a t the boiling point of the solvent,, we could afterwards detect no trace oE picric acid in the benzene. This, of course, led us to reject the supposition that the inability of silk to absorb picric acid from benzene is due t o the formation of the compound of benzene and picric acid.We then thought i t probable that the hygroscopic moisture in the silk might prevent the benzene from " wetting " it ; so that there was no action, hecause there was no real contact. This hypothesis, however, had also to be rejected, for silk dried at looo, and then kept for 48 hours in a, vacuum desiccator over sulphuric acid, showed precisely t h e same behaviour as before, whether originally dyed or undyed. There is, therefore, so far as picric acid is concerned, no transference of the dye between silk and benzene. It might still be held tohat this is due to the imperfect wetting of the silk by the benzene, but such a F-iew is untenable, for a, solution of rosaniline in benzene a t once colours dried silk.We rnnst, consequently, refer the above inactivity to some peculiarity of the whole system, or to some joint property of the benzene and picric acid. The most obvious difference between an aqueous and a benzene solution of picric acid is that in the former the acid is in a state of practically complete electrolytic dissociation, whilst in the latter it is scarcely, if it all, dissociated. If electrolytic dissociatiou is called in to explain the phenomena, we must assume tbat it is the hydrogen ions that are active in forwarding the dyeing, because the negative ions in a sodium picrate solution are as plentiful as in a solution of picric acid itself, and yet sodium picrate is not a dye in the sense that picric acid is.A consideration of other solvents afforded some con- firmatmion of this supposition. Alcohol, as we have seen, is almost as active as water; in it the picric acid is considerably dissociated (Schall, Zed. physikal. Chem., 1894, 14, 706). I n ether there is very slight dissociation and sluggish action. Carbon tetrachloride is coniparable with benzene both as regards absence of dissociation and absence of action on silk. 'In order t o ascertain, therefore, if the number of hydrogen ions present had a, preponderating influence in determining the quantity of acid absorbed, we made parallel experiments with benzoic acid alone, and in presence of its calcium salt.Benzoic acid is readily absorbed by silk, and, according to the electrolytic dissocia- tion theory, it is split up to the extent of about 6 per cent. in an aqueous solution of the concentration we investigated. Its salts, on the other hand, are highly dissociated, and the addition ofABSORPTIOS 0%’ DILUTE ACIDS BY SlLR. 1345 any soluble salt of benzoic acid to the solution of the acid itself reduces the dissociation of the latter to the vanishing point. Thus benzoic acid in presence of a large excess of calcium benzoate should be much leas absorbed by the silk than when it is in pure aqaeous solution if the presence of hydrogen ions conditions the amount of absorption. The results we obtained were as follows. The amoiint of acid absorbed by 3 grams of ashless silk from 100 C.C.of N/64 benxoic acid was 17 per cent. of the whole. A precisely similar experiment with N/64 benzoic acid in presence of 12 equivalents of calcium benzoate showed an absorption of only 1.5 per cent. of the acid present.. There was thus a very marked reduction in the amount ot‘ acid absorbed by the silk when a neutral salt of the acid was added ; a fact which lent considerable weight to the snpposition that the degree of dissociation of the acid played an important part in determining the amount of acid absorbed. Addition of alkaline benzoate, however, was found to effect no such diminution in the aniount of benzoic acid absorbed, although the degree of dissociation was thereby reduced. Further experiments on this point are in progress.Dilute Acids a i d Silk. As the electrolytic dissociation theory asserts that the strength of an acid depends on the proportion of hydrogen ions its aqueous solu- tions contain, we determined the absorption for various acids belong- ing to widely different types, in order to ascertaiu if any connection existed betweeu their strength (as measured by their dissociation constants) and the extent to which they were absorbed from equivalent solutions by a given quantity of silk. Most of the experiments were made with the silk prepared as pre- viously described, but in order to eliminate the effect of the ash in iieutralising the acids, a quantity of ash-free silk was obtained by repeated treatment with dilute hydrochloric acid. The strength of acid used was N/200, and the silk was allowed to soak in successive portions for some days. When the silk left no weighable ash on ignition, the treatment was stopped, and the silk then washed with distilled water until the washings gave no turbidity with silver nitrate solution, and were iieutral to phenolpbthalein.Tho fibre thus obtained was decidedly weaker than the silk before treatment, and was not so readily dyed with magenta. I t was, therefore, scarcely to be considered a uormal fibre, but the relation between it and ordinary silk proved to be very simple so far as action on acids was concerned. Comparative experiments were made with the silk formerly used and with ashless silk. I n each, 3 grams o€ silk were heated for1346 WALKER ISL) APPLEYARD : 42-48 hours at 60" with 100 C.C.of the various acids at various con- centrations. The quantity of the acid which disappeared when ashless silk was used mas always less than was the case for ordinary silk, and the difference was approsimntely constant. The mean difference of the 10 experiments mas equal to 2 C.C. of N/16 alkali per gram of silk, the extreme values being 1.74 C.C. and 2.34 C.C. By subtracting this mean value: therefore, from the absorptions found with ordinary silk, the numbers hold good for the ashless fibre, and in erery case the values given have been thus corrected. That the ash is contained in the silk in a form capable of nentralis- ing acids without the liberation of weaker acids, was further shown by the absorption values for sodinm carbonate being the same for both ordinary and ashless silk.The following table contains the amounts of acid absorbed per cent. for various acids under the same conditions as above, 3 granis of silk being heated with 100 C.C. of the acid solution for 42 hours at 60". In the first column are the numbers for N/16 solution, in the second, those for N/32 solution. These experiments were made with ordinary silk, and the correction for the ash has been applied. In the third column are the absorption values for N/64 solution with ashless silk. The fourth column contains the dissociation constants of the acids, which are arranged in the order of these constant,s. The result was in all cases the sinie. Acid. N,'16. Ni32. N/64. Valeric ......... 5.6 6.0 4 9 2.1 Acetic .......... 1.7 A d Benzoic......... 15.0 15.8 17.0 Succinic ....... 0 1.2 2.4 i). 7 Sulphanilic.. .... 3.2 5.0 10.0 Citric ........... 1.3 2-7 5.3 Tartaric ........ 2.0 . 2.9 6.0 Salicylic ........ 21.1 23.6 26.5 Malonic ........ 5.0 6.6 8.0 Oxalic .......... 5.0 9.3 12.5 Sulphuric ....... 3.8 5-3 11.2 27.0 39-0 Picric .......... H-jdrochloric .... 44 6.7 1 4 8 - K. 0.0016 0.0018 0*0060 0.0066 0.058 0.080 0.097 0.102 0.158 10.0 - - - Tlie values for picric acid were derived from the curve, p. 1340. Sulphuric, picric, and hydrochloric acids are so powerful that their disgociahn constants are not acc.ui*ately known. They probably, fio\\-ever, lie about 100 to 150. The concentrations in every case are molecular, not equivalent. With regard to the accuracy of the determinations, the error is atABSORPTION OF DILUTE ACIDS BY SILK.1347 ]east 1 in the unit place, SO that values differing by that amount may be held as identical, The experimental conditions are most favourable in the N/64 solutions, and as the numbers for that dilution ape also unaffected by the correction for ash, they will be used prefer- ably in comparing the different acids with each other. I t is zit once erident from the table that the strength of an acid does not alone determine the extent to which it is absorbed by silk. Succinic and benzoic acids have nearly equal constants, that is, are almost equally strong, yet the amount of absorption in the former 3ase is almost d, whilst in the latter it is very considerable. The same may be said of tartaric and salicylic acids, which have nearly equal conskants, and widely different absorption values.Citric and tartaric acids, on the other hand, have absorption values and dissocia- tion constants which are nearly the same. When we compare acids of the same type, there seems t o be, in general, increased absorption as the acids are stronger. The first three members of the oxalic acid series illustrate this most clearly. Acid. N/64. I(. O d i c .............. 12.5 10.0 Malonic ............. 8.0 0.158 Succinic 2.4 0.0066 ............ Here the constants fall off rapidly, and corresponding with this me have a marked diminution in the absorption. The introduction of hydroxyl groups would appear to raise both the dissociat.ion constant and the amount of absorption, as may be seen in the following table.Acid. N/64. K. S n cci n ic ............ 2.4 0.0066 Dihydroxysuccinic.. .. 6.0 0.097 Berizoic 17.0 0~0060 o-Hydroxgbenzoic .... 26.5 0.102 ............. There is thus a certain connection between the absorption numbers and the dissociation constants, when acids belonging to the same family are compared. Indeed, if we make even the broad dis- titiction into aromatic and non-aromatic acids, we find that in each class the constants and the absorptions run very nearly in the same order. Perhaps the most striking featme in the numbers of the preceding table is precisely this difference between aromatic and fatty acids with respect to absorption. The average absorption of the four aromatic acids investigated is 23 per cent. at the concentration N/64 ; t.hat of the seven fatty acids is 6 per cent., or only one-fourth of the VOL LXIX.4 x1348 ABSORPTION OF DILUTE ACIDS BY SILK. former number. For the two strong mineral acids, hydrochloric and sulphuric, the corresponding value, 13, occupies an intermediate position. In virtue of their high dissociation constants, these acids may be regarded rather as forming a continuation of t)he series of fatty acids than as being connected with the aromaiic acids, which have lower constants and higher absorption values. On comparing the proportions of the acids absorbed at different dilutions, i t is apparent that great differences are to be found in the conduct of the various acids. Whilst in some, notably i n valeric and benzoic acids, the amounts absorbed at the different con- centrations bear an almost unvarying ratio to the whole acid present ; in others, the proportion absorbed increases rapidly as the bath becomes more dilute.Citric acid is an extreme instance of this kind ; with it tho absolute amount of acid absorbed by a given quantity of silk is nearly independent of the dilution, although, in all probability, the experimental error here greatlly exaggerates this effect. Most of the acids are, like picric acid, midway between these two extremes. I n considering these absorption values i t should be borne in mind that they do not altogether represent the real amount of absorption. They are actually the diminution in the acidity of the dye-bath, and though this diminution is, in the case of the aromatic acids, for example, almost entirely due to the absorption of the acid by the silk, yet, in every case, the acid dissolves out of the fibre a greater or smaller proportion of soluble gummy matter, and, in doing so, is partially neutralised. The amount of this action is less as the strength of the acid diminishes, but for weak acids, such as acetic and succinic, where the absorption is very small, its effect may account for a great part of the “absorption.” We contemplate further experiments in this direction.Su mrnary. As this investigation is of a preliminary characher, we do not pro- pose, in the meantime, to draw any definite conclusions from our results; but the following general indication of the bearing of our experiments may be given. When silk is dyed with picric acid, a real equilibrium is attained, which is independent of the original distribution of the materials.I f the equilibrium concentration of the picric acid in-the silk be denoted by s, and in the water by 20, the relation s/.(t/w = constant exists between these magnitudes. This formula would indicate, according t o the solid solution theory of dyeing, that the weight of the molecule of picric acid, dissolved in water, would be n times that of the molecule of picric acid ‘‘ dissolved ” in silk ; but this we know to beACTIi)N OF LIGHT OY ANTL ALCOHOL. 1349 incorrect, as n is greater than unity and the molecular weight of picric acid in water is the smallest consistent with its formala. When other solvents than water are used, the rate and amount of dyeing with picric acid seem to be connected with the dissociatire power of the solvent. Silk will not take up picric acid from benzene or from carbon tetrachloride, but does so readily from alcohol, less readily from ether and acetone. The ratio of the final concentrations of aqueous and alcoholic solutions of picric acid required to dye silk to a given standard, was found to be tipproximately the ratio of the solubilities of picric acid in water and i n alcohol. A comparison of the extents to which various acids are absorbed by silk, shows that the acids fall naturally into two classes-the aromatic acids, where the absorption is great, and the non-aromatic acids, whhere the absorption is relatively small. I n each class there is a rough parallelism between the strength of the acids and the amount absorbed. The addition of calcium benzoate to ,z solution of benzoic acid greatly diriiinishes the absorption of the acid, but alkaline ben- zoate has no such effect. If dyeing were a purely chemical addition of the dye to the fibre, the theory of mass action predicts that the equilibrium concentration of the dye-bath should be constant a t any given temperature, inde- pendently of the quantities of material taken. This is not known to be the case for actual dyeing, but i t was experimentally verified by " dyeing " diphenjlamine with picric acid from aqueous solutiog.

ISSN:0368-1645    

DOI:10.1039/CT8966901334

出版商:RSC    

年代:1896

数据来源: RSC