摘要:

FRANKLAND AND PRTCF,: THE AMTL DERIVATIVES, ETC. 253 XXI.-The Amyl (secondcwy Butyl-methyl) Dekuatiws of Glyceric, Diacetylglyceric, and Dibenxoylglyceric Acids, Active awl Iqmctive. By PERCY FRANKLAND, Ph.D., B.Sc., F.R.S., and THOMAS SLATER PRICE, B.Sc., late Priestley Scholar in Mason College, Birmingham. THE preparation of the above derivatives is attended with particular interest for several reasons. Firstly, because, in the series of glycerates and diacetylglycerates, i t has been shown by one of us that a maximum rotation is attained," and that this maximum falls, either on the butylic, amylic, or hexylic terms of each series, and of these three terms hitherto only the butylic has been prepared. One of the objects of this investigation was, therefore, to ascertain whether the possession of the maximum really rests with the butylic term, or whether the rotation of the latter is surpassed by that of the amylic compound. Again, in the case of the series of the dibenzoylglycerates, only the methylic, ethylic, and propylic compounds? have so far been studied, so that the preparation of the amylic term should materially increase our knowledge of the rotation phenomena exhibited by this series.Lastly, the amyl radicle can be introduced in both an active and an inactive (racemised) form, so that the effect of one asymmetric carbon atom on another can be submitted to examination. It might at first sight appear unfortunate for the success of this investigation that active amylic alcohol is not known in a pure state, but it will be readily understood that, for the first two purposes mentioned above, the principal interest lay in the introduction of the inactive (racemised) amyl radicle, so as to enable a comparison to be instituted between the rotation of the amylic compound of the active acids in question, and that of the compounds of these acids already prepared, all of which compounds haT-e contained inactive radicles only.Again, as regards the last purpose referred to above, it has been repeatedly shown$ that comparative rotation results are obtained in working with a mixture of an active compound and its mcemoid, provided the proportion between the two constituents of the mixture remains invariable throughout. The amylic compounds which we have prepared have all been obtained from one and the same amylic alcohol, exhibiting a lavo- rotation, [ = - 4-62', * Percy Frankland and MacGregor, Trans., 1893, 1410 ; 1894, 750..t. Percy Frankland and MacGregor, Trans., 1896, 104. $ Guye and Chavanne, Cornpt. rend., 1894. VOL, LXXI, T254 FRAWKLAND AND PRICE: THE AMYL DERIVATIVES OF and, for the purposes of this investigation, this may be regarded as the rotation of pure lzevo-amylic alcohol. It is obvious that, of any of the above three acids, no less than nine amylic compounds can be prepared ; for instance, in the case of glyceric acid, (1) Aniylic (dextro) glycerate (dextro). (8) Amylic (lsvo) glycerate (dextro). ( 5 ) Amylic (inactive) glycerate (dextro). (7) Amylic (dextro) glycerate (inactive). (2) Aniglic (IEVO) glycerate ( l ~ v o ) . (4) Amylic (dextro) glycerate (lsvo).(6) Amylic (inactive) glycerate (lsevo). (8) Amylic (lzevo) glycerate (inactive). (9) Amy1 (inactive) glycerate (inaative). Of these (5) is really a mixture or compound of (1) and (3) 9 9 (6) > 9 7, 7 ) 9 7 (2) 7 1 (4) 9 , ( 7 , 9 ) 9 9 9 , 9 9 (1) 9 , (4) 9 9 (8) 7 ) Y7 Y ) . Y J (2) Y ? (3) 9 9 (9) 7, 7 7 79 9 9 (I), (2), (3)Y and (4), or of (5), ( 6 ) , (7)Y and (8). No. (9), being devoid of rotatory power, is without interest for us, and can, therefore, be dismissed for the present. The materials a t present at our disposal for the preparation of these compounds are (a) inactive amylic alcohol (secondary butylcarbinol) (obtained by racemising the original alcohol), (6) Isvo-amylic alcohol, ( c ) inactive glyceric acid, and ( d ) dextro-glyceric acid (obtained by fermentation of the inactive calcium glycerate by the bacillus et?Aace- ticus").To these might be added dextro-amylic alcohol obtained by Le Be1 (Bull. Xoc. Chim., 1879 [ 2],31, 104, and Compt. vend., 1878.87, 213) by the growth of moulds in the racemised alcohol, but for practical purposes this material may be excluded from the list. The rotation properties of all these eight ethereal salts can, however, be evaluated from a knowledge of those properties for (5) and (8) alone, by the use of two principles. a. That the optical antipodes have the same rotation, but with opposite sign. p. That the optical effect of each asymmetric carbon atom is exerted independently of that of the other asymmetric carbon atoms which may be present in the molecule, the optical effect of the whole molecule being the algebraic sum of the optical effects of the several asymmetric carbon atoms which it contains.? Thus let the rotations of ( I ) = & (a)=& (3)=C, (4)=D7 (5)=E, (6)=Fy (7)=G, (8)=H, then E+H=C, but C = -D, again E= -F and H= -G, but E+G=A and A = -B.Thus A, B, C, D, E, F, G, and H are all known. * Percy Frankland and Frew, Trans., 69, 1891, 96. f Guye and Gautier, Conipt. rend., 1894.GLTCERIC, DIACETYLGLYCERIC, ETC., ACIDS 255 Inthe present investigation, we have prepared (5) and (8), as well as (l), not only for glyceric, but also for diacetylglyceric and diben- zoylglyceric acids respectively. We have thus tested the second of the above principles, and it will be shown that we have found it to hold good ; the first principle is so well established that it would be almost waste of time to test it further, so that by means of the above formula+ the rotation of all the eight compounds can be calculated.Thus, of the three acids, we have obtained the rotation of 24 compounds and molecular mixtures by the actual preparation of 9, and have thus shown that the preparation of 6 would have been really sufficient for the purpose. H ~ 7 , j l l l i c illco/iol ( A ~ e c o n r ~ w y hzctylcwbiiaol), CH,&CH,OH. I C,H, The amylic alcohol used in this investigation was hvo-rotatory, giving an= - 7.53" in a 200 mm. tube at 15.3". An attempt mas made to further purify it by fractional distillation, and in this may two fractions were obtained, distilling a t 128-130" and 130-131" respectively. The activity of these two fractions mas, however, so similar, namely aD = - 7.64" and - 7.42" in a 200 mm.tube, that it would have served no useful purpose to employ them separately, and, therefore, the original alcohol was used throughout. I t s density was d 11"/4" = 0.8237, and its specific rotation a t 11" [ a]J'" = - 4-62", As, for some of our proposed compounds, this alcohol was required in an inactive state, me endeavoured, in the first instance, to racernise it by means of sodium hydroxide. For this purpose, 30 C.C. of the alcohol were boiled with 0.5 gram sodium hydroxide for 4 hours, using a reflux condenser. On subsequent distillation, i t passed over at, 1 29-131°,_and on polarimetric examination gave, aD= - 7-52' in a 200 mm.tube a t 15". This treatment had, therefore, practically left its activity unchanged, The treatment was repeated, using a much larger quantity of sodium hydroxide; 45 grams of the alcohol were heated on the water bath with 40 grams of sodium hydroxide for 7 hours. The sodium hydr- oxide was appreciably dissolved, but a large excess remained unaffected. The alcohol was poured off from the sodium hydroxide, and the latter washed several times with cold water, the washings being added t o the alcohol. The alcoholic liquid was then acidified with sulphuric acid, and the alcohol separated from the aqueous layer. The former was dried with sodium hydroxide and then distilled; it passed over a t 12'7-129", and gave, a,,= - 7.1" in a 200 mm.tube at 16". The activity had thus been but little affected by the treatment. T 2 . .256 FRANKLAND AND PRICE: THE AMYL DERIVATIVES OF I n the next instance, 25 C.C. of the alcohol, which had been treated as above, were heated in a sealed tube with 0.5 gram of sodium hydroxide at 170" for 7 hours. On subsequent distillation, the alcohol came over at 129" and exhibited a, = - 4.85" in a 200 mm. tube at 15.5". The activity had thus been materially reduced, but by no means destroyed. Finally, the racemisation was effected by heating 40 grams of the alcohol on a water bath and adding 4 grams of metallic sodium in small portions a t a time; the whole of the sodium, however, did not dissolve. The amylate, which was liquid at loo", was poured off from the sodium into a pressure tube, which was then sealed and heated for 3 hours at 206". The amylate was then treated with a slight excess of hydrochloric acid, and the alcohol separated and dried over lime; the greater part of it distilled at 129O, and was found t o be quite inactive.All the inactive alcohol referred to in the following pages was prepared in this way. Anaglic (active) Glycewbte (incictice.) This was prepared in the manner already frequently described by one of us in connection with other ethereal salts of glyceric acid. The glyceric acid, obtained from 35 grams of inactive calcium glycerate, was divided into two portions, concentrated to a syrup, and each por- tion heated along with 40 C.C. of active amylic alcohol in a sealed tube for 8 hours a t 150". On opening the tube, the excess of alcohol * was distilled off under reduced pressure below SOo, the amylic glycerate subsequently passing over at 150-157" (about 9 mm.pressure). The yield was 25 grams. This crude product was dried over calcium chloride, and then purified by fractional distillation until of constant rotation; the final boiling point was 144-147" (about 5 mm. press,), The amylic glycerate thus obtained was a fairly mobile liquid of un- pleasant odour and bitter taste. On combustion, the following results were obtained. 0.2542 gave 0.5073 CO, and 0.2192 H,O. C = 54.42 ; H = 9.58 0.2580 ,, 0.5150 ,, ,, 0.2170 ,, C=54*43; H=9*34 0,2181 ,, 0.4350 ,, ,, 0.1796 ,, C = 54.39 ; H = 9-15 C,H,,04 requires C = 54.54 and H = 9.09 per cent. * This excess of alcohol was dried over lime, and after distillation (b.p. 126-129") it gave a specific rotation [ U ] ~ ~ ~ * C O = - 4'76" and density 11'4"/4" = 0.8233. The rotation is thus slightly higher than that of the original alcohol, showing that one of the constituents had etherified more perfectly than the other. This does not, however, necessarily mean that the dextro-amylic alcohol had etherified more rapidly than the lsvo-compound, for all active amylic alcohols hitherto prepared probably contain some iso-amylic alcohol, CH(CH,); CH,. CH,' OH, and this is known to etherify more easily than the active alcohol-in fact, on this property depends Le Bel's method (Corn@. rend., 77, 1021) of purifying the active alcohol.GLYCERIC, DIACETYLGLYCERZC, ETC., ACIDS, 257 Rotation of Anqlic ( w ctive) G Zycemte (iwict h e ) .Observed rotation Deiisity compared 11" + 2-85" 1.0807 (experiment) + 2-86' 47 + 2-71 1.0505 ( ,, ) +2.79 25.5 4-2 75 1.0685 (interpolated) + 2.79 11% + 2.90 1.0802 ( ,, ) +2*91 Temp. a~ in 92.35 mm. tube with water a t 4". [ Q l D The activity of this substance is, therefore, hardly a t all influenced by temperature ; if anything, with increase of temperature, the positive rotation diminishes very slightly, but the change is hardly, if at all, beyond the range of experimental error as can be seen from Fig. 1. FIG. 1. -Specific Rotation of Amylic Glycerates. loa 15O 20° 25a 30° 360 400 450 500 55" + 20 + I 0 00 - 10 - 20 -30 - 40 - 50 - 6 O d 7 0 -. \ -8" -90 - 100 - 110 - 120 - 1 3 O - 14' - I 5 O loo 15' 20° 25O 30° 3 5 O 400 450 500 55- i'imipcrubtm C Anzglic (active) Biacetplylyceiw& (inactive).Twelve grams of the above alnylic glycerate were gradually added to twice the calculated quantity of acetyl chloride heated to 50". When the reaction had ceased, the excess of acetyl chloride was distilled off under reduced pressure, the diacety lglycerate subsequently passing over at 163-165" (about 12 mm. press.). Sixteen grams of this crude product were obtained, which was distilled until of constant rotation. The amylic diacetylglycerate is a more mobile liquid than the amylic glycerate; it has a peculiar odour and bitter taste.258 FRANKLAND AND PRICE: THE AMYL DERIVATIVES OF On combustion, it gave t,he following resulh, -2286 gave 0.4620 CO, and 0.1600 H,O. Ct = 55-12 ; H = 7.77.~2138 ,, 0.4327 ,, ,, 0.1524 ,, C: = 55 19 ; H =- 7-92. U,,H,,06 requires C = 55-38 and H = 7-69 per cent. Xotatioiz of A~nylZ'c (act iue) Diacetylglycerute (inactive). Temp. aD in 92.35 m i x tube. with water a t 4". r410. 11" + 1.67" 1.0S63 + 1-66 49.7 + 1-62 1 *0488 + 1.67 The density determinations made were d 1 l0/4" = 1.0863 and d 50"/4" = 1 -0485. The substance is, therefore, practically insensitive t o terupera- ture as regards specific rotation. Observed rotation Density conipared (See Fig. 2.) 4 5 0 0' q-IC 1 2L -20' -25' -30 FIG. 2 -SSperific lhtation of Amylic Diacetylgljcerates. loo 20° 30° 40" 50" B O O 70° 80' 90° 100" 10' 20" 30' 40" 50' 60' 70° 80 90° looo Antplic (active) Diben,-,.oyglycemfe (imctive). 14-5 grams of amylic (active) glycerate (inactive) were added slowly to twice the theoretical quantity of benzoyl chloride, which was heated to 1 3 5 O , and finally to 160°, until reaction was complete.The ex- cess of benzoyl chloride was distilled off under reduced pressure, the crude product, which weighed 17 grams, subsequently passing over at 262-268" (about 7 mm. press.). After redistillation, the ethereal saltGLYCERIC, DIACETYLGLYCERIC, ETC., ACIDS. 259 crystallised for the most part ; it was repeatedly recrystallised from methylated spirit until of constant melting point (36-36.5"). It was also obtained in a crystalline form from light petroleum, methylic alcohol, ethylic alcohol, ether, acetone, and benzene. Recrystallisa- tion from isobutplic alcohol did not affect the melting point.The crystals were prismatic, and terminated by pyramidal faces. 0,15775 gave 0-3958 CO, and 0.0900 H,O. C = 68.43 ; H = 6.34. 0-2029 ,, 0.5101 ,, ,, 0.1151 ,, C = 68.56 j H= 6.30. C,,H,,Oo requires C = 68.75 ; H = 6.25 per cent. Rotc&ou of AmyIIZ'c (active) Dibe?z~oylgZ?lcei.ate (imict ice). 'l'eii11). a,, in 92-35 nim. tube. with water at 4". [a],,. 36%" + 1.77" 1 a 1 265 + 1.70' 37 3- 1.79 1,1262 + 1.72 99 + 1.59 1,0755 . + 1-60 Observed rotation Density compared The density determinations actually made mere d 40"/4" = 1.1 237 and d 99. "14" = 1.0749. * P f + 20' FIG. 3. --Specific Rotation of Aniylic Dibenzoylglycerates. loo PO0 30" 40° 50" 60" 70" 80" 90" looo +35' +300 125" f200 '100 + 5 0 10' 20' 30° 40' KOo Soo 70° 80' No looo Emperatwe C The specific rotation is thus hardly affected by temperature (see Fig.3) ; its rotation in benzene solution was also determined for several concentrations.260 FRANKLAND AND PRICE: THE AMYL DERIVATIVES OF Kotc~, t io n of A way 2 ic ( CLC t ive ) D ibenzo y lg Zy cem t e ( i?z a c t ive ) in Benzei ae Solution.-It has been shown by one of us (Percy Frankland and Pickard,Trans., 1896,69,128) that methylic dibenzoylglyterate (active) gives a higher specific rotation in benzene solution than when examined in the superfused state, and, further, that the specific rotation is the greater the more dilute the solution. It appoared, therefore, of interest to ascertain what would be the behaviour in this respect of amylic (active) dibenzoylglycerate (inactive) ; the rotation of the latter in benzene solution was determined with the following results.Rotation of Amylic (ccctive) Dibeizxo?lZglycei.ate (inactice) in Benzene Solution. [a], in liquid state = + 1*70" Grains of Density Observed Granis of Granis of 100 grams with water 198.4 mm. ester i n compared rotation a, in Temp. ester. solvent, solution. a t 4". tube. Lu1D. 16" 1'0026 17.8874 5.31 0.8941 + 0.20" -t 2-12" 16 3'6531 15'3407 19'23 0.9247 +0'74 3.2'10 18 5'1362 13.6831 27-29 0.9409 + 0 9 7 +1'90 The specific rotation in benzene solution was thus found to be slightly but distinctly in excess of that of the pure substance in the fused state, and to diminish slightly with increasing concentration. We have also determined the rotation of the active amylic alcohol in benzene solution with the following results.Rotcction of Active Anzylic Alcohol in Benzene Solution. Rotation of the pure alcohol [.ID =; - 4-62. Grams of alcohol in Grams of Grams of 100 grams Temp. alcohol. solution. solutioii. 16" 1-0743 18.7769 5-72 16 3.3642 18'8512 17'85 16 5.3199 19.9857 26'62 16 6'1978 19*6058 31.61 Density compared with water a t 4". 0.8779 0.8688 0'8626 0.8595 Observed rotation in 198'4 nm. tnbe. [a],. - 0'41" - 4.11" -1.26 -4.10 -1.83 -4.02 -2.24 -4.15 Thus the negative specific rotation of the amylic alcohol is less in benzene solution than in the pure state. Sapon$cation of Amy& (uctive) Bibenxoylglyce~ute (inuctiue) .-This was effectedinorder toascertain whether the amylicalcohol recovered had the same activity as the amylic alcohol originally employed, or whether any change had been effected through its transformation, firstly, into amylic glycerate, and subsequently into amylic dibenzoylglycerate.Twenty-five grams of the ethereal salt were mixed with twice the theoretical quantity of baryta dissolved in water, and heated for 55 hours on a water bath, using a reflux condenser, it had disappeared. The liberated alcohol was removed by steam distillation, and separated from the aqueous distillate by adding common salt, and ultimately byGLYCERIC, DIACETYLGLYCERIC, ETC., ACIDS. 261 shaking out with ether. After drying with potassium carbonate and distilling off the ether, the amylic alcohol passed over at 128-129". A blank experiment was also made, in which some of the original amylic alcohol was digested with baryta and otherwise similarly treated in every partic:ular.On polxrimetric examination, these two specimens of amylic alcohol gcve the following results. Amylic alcohol (from blank experiment). QD = - 1.86" in 50 mm. tube a t 17.8". d 17*8"/4" = 0.8192 .. - [ ,ID1'7'8" = - 4.54". Amylic alcohol (from saponification of the ethereal salt.) [all) = - 1.94" in 50 mm. tube at 17", assuming this t o have the same density as the other specimen, then the original alcohol had the specific rotation [ ~ ] ~ l l " = - 4%2", thus the difference between the two is very slight. [ ,ID1'7" = - 4.73" Am~Zic (active) Glycei-ate (active). This was prepared in the same way as the amylic glycerate described above, excepting that active glyceric acid (destro) was used.It distilled at 144-148" (about 6mm. press.). 0.2034 gave 0,4063 CO, and 0,1662 H20. C = 54.48 ; H = 9.08. 0.1799 ,, 0.35805 ,, 0.1500 ,, C ~ 5 4 . 2 8 ; H- 9.26. C,H,,O, requires C = 54.54 ; H = 9.09 per cent. Rotation of AmgZic (active) Glgcemte (active). Observed rotation a in 92.35 Density compared Temp. mm. tube. with water a t 4". [a]? 45 - 11.44" 1,0512 - 11.78 12.5" - 11.48" and - 11.51" 1.0785 - 11.34" The density determinations actually made were d 12'14" = 1.0789 and d 45'14" = 1.0512. The specific rotation of this substance is, therefore, but slightly affected by temperature, but in so far as it is, the negative rotation increases with rise of temperature, ashas already been found by one of 11s (P. Frankland and MacGregor, Trans., 1894, 65, 760) to be the ca,se with other simple ethereal glycerates.The excess of amylic alcohol recovered in the preparation of this amylic glycerate was dried, distilled, and found t o possess the rotation [ a j21'G " = - 4.71" and density cl 11 *6"/4" = 0.8228. Thus, like the excess alcohol recovered in the preparation of amylic (active) glycerate (inactive), it had a slightly higher rotation than the original alcohol employed (see p. 255).262 FRANKLAND AND PRICE: THE AMYL DERIVATIVES OF Amy& (active) Bincetylg Zycerate (active). This was prepared in the same way as the corresponding compound As usual, it was fractionally distilled until of con- The boiling point was 152-157" (under a pressure of described on p. 257. stant rotation. about 6 mm.). 0.1876 gave 0.3786 GO, and 0.1290 H,O.C = 55.04 ; H = 7.64. 0.1867 ,, 0,3768 ,, 0.1322 ,, C=55*04; H=7*87. C1,H,,O, requires C = 55.38 ; H = 7.69 per cent. Ziotcition of Anzylic (active) Diacetylglycemte (active) . Tc 1 I1 1). u' in 44 inm. tube. with water a t 4". [a]*,. 1 1 -4" - 8.25" 1,0855 - l'i.27" 37.7 - 8-67 1.0587 - lS.61 99.5 - '3.35 0.9990 - 21.27 0 bser ved ro tat ion Den si ty coiiip a red After taking the rotation a t this high temperature, it was again observed at 11.4", and found to be exactly the same as a t first. The density determinations actually made were tl 11*4"/4" = 1.0855, cl 38"/4" Thus the specific rotation of this compound, like all the other diace- tylglycorates previously examined by one of us, is very markedly affected by temperature, the negative rotation increasing with rise of temperature.As seen from the diagram, the increase in specific rotation is almost exactly proportional to the increase in temperature (see Fig. 2, p. 258). = 1.0584, d 100"/4" = 0.9985. Amy& (active) Dibemopllglycemte (active). I. This was prepared in exactly the same way as the corresponding compound described on p. 258, excepting that amylic (active) glycerate (active) was employed. I t distilled a t 255-270" (at about 4 mm. pres- sure) ; it was slightly yellow, and was viscid, but less so than the amylic (active) dibenzoylglycerate (inactive). A s all attempts to obtain it in a solid form were unsuccessful, it was dissolved in ether, washed with a strong solution of sodium carbonate, and then with water ; the ether was removed by distillation, and the residue dried in a vacuum-desiccator.aD= + 11.49" in n 50 min. tube a t 14". It was again distilled under reduced pressure, but at the end of the process the flask burst, and the di3tillate was darkened. The latter was, therefore, again distilled, the distillate being further washed and dried as above. al,= + 11.26" in a GO mm. tube at 16". The rotation was then found to be The rotation was then found to beGLYCERIC, DIACETYLGLYCERIC, ETC., ACIDS. 263 The rotation was thus slightly lower than before, but the temperature was higher, and i t will be seen below that the rotation is very sensi- tive to temperature. Analysis also showed it to be as pure as we were able to obtain any of the other liquid dibenzopl compounds, thus, 0.19875 gave 0.4968 CO, and 0.1131 H,O.C = 68.17 ; H= 6.32. 0.1944 ,, 0.4877 ,, 0.1131 ,, C=68*42 ; H=G.46. 0.19195 ,, 0.4797 ,, 0.1097 ,, C=68*16; H=6*35. 0.2000 ,, 0'4997 ,, 0.1161 ,, C=68*14 ; Hr6.45. C,,H,,O, requires C: = 68.75 ; H = 6-25 per cent. Rotcition of flitL?jZic (active) Dibeiaxo?lZ~Z?lcei.cite (c6ctizje). ( P i m t specinaeib) 0 bse r ve cl rot a t io ii D e 11 sit y coin pa re cl Te1np. au in 44 iiini. tube. with water a t 4". [UIU. 16" D + 9.96" 1.1466 + 19.76" 17 + 9.84 1.1446 + 19.54 42.5 + 9.10 1.1213 + 18.44 51.8 + s-75 1.11336 + 17-86 99.3 + 6.59 1.0750 + 13.93 The density determinations actually made were t l 16*5"/4" = 1.1451, From the above figures, it will be seen that the rotation is extremely sensitive to temperature, and, as in the case of those dibenzoglgly- cerates previously investigated by one of us, the positive rotation diminishes with rise of temperature.On plotting the rotations as a curve, it will be seen (see Fig. 3, p. 259) that the latter approaches more and more t o a straight line the higher the temperature, the rotation becoming also more sensitive as the temperature rises. The figures for the density, on the otlier hand, show that this diminishes more and more slowly with rise of temperature. 11. I n consequence of the accident which happened to the above specimen of amylic (active) dibenzoylglycerate (active), and the possi- bility of this having influenced the rotation observed, we deemed it desirable t o prepare a further quantity. Unfortunately, we had ex- hausted our original supply of active amylic alcohol, and the new preparat,ion had to be made from a fresh sample.The rotation of the new amylic alcohol employed was found to be very slightly higher than that of the former one, namely, aD= - 7.61" in a 200 mm. tube a t 12.5". The amylic (active) glycerate (active) prepared from it had also a slightly, but distinctly higher, rotation than the former specimen, thus cl 43'14" = 1.1208, d 52"/4" = 1.1132, d 99.8"/4" = 1.0746. * This observatioii was made a t the end of the series, and thus slioxs that the rotation has not been affected by raising the substa;nce to the temperatures employed in the otlier observations.264 FRANKLAND AND PBICE: THE AMYL DERIVATIVES OF a,,= - 6.60" in a 50 mm. tube at 20.5" (new specimen).-6.14" ,, > 9 19" (former specimen). From this new specimen of amylic (active) glycerate (active), the dibenzoyl-compound was prepared as before. 0.1841 gave 0.4608 CO, and 0.1078 H,O. On combustion, C = 68.26 ; H = 6.50. The substance was thus of about the same degree of purity as before. It was again distilled, but the distillation was not found to have altered the rotation. On combustion again, U.lSOS gave 0.4520 GO2 and 0.1034 H,O. C = 68.18 ; H = 6.35. C,,H,,O, requires C = 68.75 ; H = 6.25 per cent., thus showing that no further purification could be effected by dis- tillation. The rotation was then determined over the following range of temperature. Rotation of Anaylic (uctive) Dibemoylglycemte (active). (Second specimen .) Observed rotation Density compared Temp.an in 44 mm. tube. with water at 4". [@ID. 17" + 10.31" 1.1425 + 20.51" 45.5 + 9.35 1.1180 + 19-01 74 + 8.11 1,0943 + 16.84 99.5 + 6.87 1.0739 + 14.54 The density determinations actually made were d 17.5"/4" = 1,1421 ; d 46"/4" = 1.1176 ; d 74"/4" = 1.0943 ; d 99.5"/4" = 1.0739. The altera- tions, both in density and rotation, are of exactly the same character as i n the case of the previous specimen. It 1s worthy of remark that, of the two specimens of amylic (active) glycerate (active), the one with the higher rotation also gave the more active dibenzoyl-compound, showing how the rotation of a deriva- tive is proportional to the rotation of the original mixture of the active compound and the racemoid from which it is prepared, as pointed out in the introduction.Amylic (ifinactive) Glycevate (active). This was prepared in the same manner as the corresponding com- pounds already described, excepting that inactive nmylic alcohol waa employed instead of the active ; twenty-six grams of crude ethereal salt were obtained from 35 grams of calcium glycerate (active) and 80 c.cg of amylic alcohol (inactive). It had a rotation, which was constant on redistillation, of uD= - 7.66" in a 50 mm. tube at 20". On combustion,GLYCERIC, DIACETYLGLYCERIC, ETC , ACIDS. 265 0.1'736 gave 0.3450 CO, and 0.1425 H,O. C = 54-20 ; H = 9.12. 0.1593 ,, 0,3183 ,, 0,1316 ,, C=54.49; H=9*18. C,H,,O, requires C = 54.54 ; H = 9-09 per cent, Rotation of AntyZic (inactive) Glycerate (active). Observed rotation Density compared Temp. an in 44 mm.tube. with water at 4". C.ID. 14.3" - 6.72" 1.0783 - 14-16' 16 6.70 1.0777 - 14.13 48 - 6.68 1 *0496 - 14046 The density determinations actually made were d 14.8"/4" = 1.0779 ; The negative specific rotation of this ethereal salt thus increases The excess of alcohol recovered in the preparation of this amylic d 48'14" = 1.0496. very slightly indeed with rise of temperature (see Fig. 1, p. 257). (inactive) glycerate (active) proved to be slightly active, thus, [a]D1" = - 0.085" ; d 17"/4" = 0'81 89. It has been pointed out (see pp. 256 footnote, and 261) that the alcohol recovered in the preparation of amylic (active) glycerate (inactive) and of amylic (active) glycerate (active) exhibited a slightly increased nega- tive rotation as compared with the alcohol used, the increase in each case being about the same in amount.I n these cases, as already pointed out, this may be due to the iso-amylic alcohol (isobutylcarbinol), which is doubtless also present, etherifying more readily than the active amylic alcohol (secondary butylcarbinol), but in the present case the slight activity of therecovered alcohol cannot be thus explained, and can only be accounted for on the supposition that the dextro-amylic isomer of the racemised alcohol is more readily etherified by the dextro-glyceric acid than the lzevo-amyl isomeride. This result, although suggestive, in- volves such a very small absolute rotation, that it mould be premature to draw conclusions from it yet, and me propose submitting the matter to further investigation.The possibility of some of the ethereal salt having passed over with the alcohol must also be kept in view, Amy Zic (inuctive) Diacetglgly cerute (active) . This mas prepared from the above amylic (inactive) glycerate (active) in precisely the same manner as already described in the case of the corresponding compounds. Seven grams of amylic glycerate yielded 11 grams of crude amylic diacetylglycerate. The pure product distilled at 156-159" (about 4 mm, press.), the oil-bath being at 200". On combustion, 0,1623 gave 0,32905 CO,, 0.1 162 H,O. C = 55.29 ; H = 7.95. 0.1585 ,, 0.32105 ,, 0.1115 ,, C=55*24; H=7*82. C,,H,,O, requires C = 55.38 ; H = 1-69 per cent.266 FRANKLAND AN11 PRICE: THE AMYL DERIVATIVES OF A'otntion of Amylic (inctctive) Diacetylglycei*ate (actice).Observed rotation Density compared Temp. aD in 44 mm. tube. with water at 4". [a]=. 15.2" - 9.26" 1.0813 - 19-46" 52 - 9.81 1 *0447 - 21.34 99.7 - 10.22 0.9980 - 23.27 The density determinations actually made were d 15*2"/4" = 1.0813 ; The specific rotation is thus highly sensitive to temperature, its negative value rising with increase of temperature. The influence of temperature on the rotation is exhibited in the diagram (see Fig. 2, p. 258). Amy lie (imccct ice) Dibenxoylglycernte (active). The method of preparation was the same as that pursued in the case of the two similar compounds described above, the amylic (inactive) glycerate (active) referred to on p. 264 being used as the source. It could not be obtained in a solid state. ~l 52.14" = 1.0447 ; d 100"/4" = 0.9977. On combustion, 0.19825 gave 0,4949 CO, and 0.1 155 H,O.G' = 68.08 ; H = 6.47. 0.1936 ,, 0,4836 ,, 0.1142 ,, C=68*12 ; H=G 55. U,,H,,O, requires C = 68.75 ; H = 6.25 per cent. It was, therefore, of about the same degree of purity as the other liquid dibenzoyl-compounds described above. Rotation of Amy& (inactive) Dibenxoylglycemte (nct ive). Observed rotation Density compared 16" + 9.205" 1.1452 + 18-27' 38.5 + 8-60 1.1238 + 17.39 63 + 7.66 1 ,1032 + 15.7s 100 + 5.93 1.0730 + 12.56 Temp. a, in 44 mm. tnbe. with water a t 4". [ a l D . The density determinations actually made were d 16"/4." -- 1.1452 ; d 39"/4" = 1.1236 ; cl 63'14" = 1.1032 ; cl 100"/4" = 1.0730. Thus the density diminishes less and less rapidly with rise of temperature, as in the dibenzoyl-compound described on p.263, as, in the latter case also, the specific rotation diminishes more and more rapidly with rise of temperature. These relations are best seen in the diagram (Fig. 3, p. 259). Superposition of the Opticul E f e c t s of Two Asyrrzmetiic Cwbon Atoms. One of the points of interest in connection with the compounds described in this paper lies in the circumstance that in all of them there are present two asymmetric carbons, each of which can be present (a) in the dextro-rotatory, ( b ) the lsvo-rotatory, and ( c ) in theGLYC ERIC, DIACETY LGLPCER IC, ETC., ACIDS. 267 racemoid form, I n the liquid state, however, there is no evidence t(l1at the racemoid form is anything else than a mixture in equal pro- portions of the dextro- and ltevo rotatory forms. As the optical activity of asymmetric carbon compounds, moreover, has reference to the liquid state only, i t is obvious that the true racemoid form dis- appears from consideration.The several amylic glycerates described above may therefore be thus regarded. 1 molecnle lsevo-amylic dextro-glycerate. 1 molecule lsevo-amylic dextro-glycerate. 1 molecule lzvo-amylic dex tro-glycerate. 1 molecule hvo-amylic lawo-glycerate. 1 molecule laevo-amylic dextro-glycerate. 1 molecule dextro-amylic -r dextro-gl ycerate. 1. Anzylic (Zcevo-mt.) gIpei*ate (dextro-act.) J 2. Amylic (7cet.o irct.) glycevcrte (hznct.) J [a];= c * [ a ] D = H 3. Antyldc (innct.) glycerate (tlexti-o-nct.) [.ID = E If, then, tlie optical effect of (2) be algebraically added to the optical effect of (3), the optical effect of (1) should be obtained, because the optical effect of 1 mol. I-amylic I-glycerate will be equal, but opposite in sign, to that of 1 mol. d-amylic d-glycerate, and therefore these will destroy each other, and there will remain the optical effect of 1 mol.I-nmylic cl-glycerate from (2) + the optical effect of 1 mol. I-amylic d-glycerate from (3), which slim will thus equal the optical effect of (1). This is actually found to be the case, thus, comparing the specific rotations a t the same temperatures, Antylic (Zcwo-ccctive) glycercite (iniict ive). Anzylic (inactive) ylycerccte (tlext?*o-nct ice). I n other words, H + E = C. H [ = + 2.86'. [a1,477 = + 2-$9". E [a],>*" = - 14.13". [~]1)'1''= - 14.45".I€ + E = C! Then, for 11". Amylic (law0 active) glycerate (dextro-active) [ 2.S6 - 14.13 = - 11.27" =[a], amylic (IEvo-active) = - 11 *53" (by glycerate (dextro-active) (by calculation). experiment). Difference between calculation and experiment = 0.26". Again, for 47". +t We have adopted the same lettering here as in the introduction, p. 254.268 FRANKTJAND AND PRICE : THE AMPL DERIVATIVES OF H + E = C 2.79 - 14.45 = - 11-66' = [ a ] , amylic (laevo-active) glycerate (dextro- Amylic (laevo-active) glycerate (dextro-active) [ u = - 11 *79" (by active) (by calculation). experiment). Difference between calculation and experiment = 0-1 3". Applying the same reasoning to the amyl diacetylglycerates, we Amy Zic (Zcevo -active) dia cety Zgly cerccte (inactiue).Amyl (inactive) diacetylglycemte (dextyo-active). Then H + E = C have, H [U],"" t-- + 1.66". [a],52"= + 1'67". [,]D99'70 = + 1.68". E [aID1l"= - 19.25". [a],52" = - 21.34". = - 23.2'7". [ a]D for amylic (lsvo-active) diacetylglycerate (dext,ro-active), Calculated. Found. Difference. A t 11" 1.66" - 19.25" = - 17.59" - 17.25" 0.34" I 9 52 1.67 -21.34 = - 19.67 - 19.22 0.45 ,, 99.7 1.6s -23.27 = - 21.59 -21.28 0.31 Similarly, in the case of the amylic dibenzoylglycerates, Amylic (lcevo-active) dibenzoylglycerate (inactive). H { [alD16" = + 1.76". [a]D630 = + 1.67". [ u ] p ' s " = + 1.72. [ a]DIOOO = + 1.60. Am, y lic (inactive) dibenxo y lgl ycera te (dextro-act ive) . = + 18.27". - +15*78". { E"1D'60 0 , ] ~ 3 8 ' ~ = + 17.39" [ a]D1oo" = + 12 '5 6. Then H + E = C = [a], for amylic (lmo-active) dibenzoylglycerate (dextro-active). Calculated.Found. Difference. At 16" 1.76" + 18.27" = + 20.03" + 19.76" 0.27" ,, 38.8 1.72 +17*39 = +19*!1 +18*62 0.49 $ 7 63 1.67 +15*78 = +17.45 +16*93 0.52 7, 100 1.60 +12.56 = +14.16 +13*S7 0.29 The experimental are thus in all cases in close agreement with the calculated results, and thus show the feasibility of calculating the rotation values of all the optically isomeric amylic glycerates, diacetyl- glycerates, and dibenzoylgiycerates, provided the values H and E are determined in each series, asindicated in the introduction on p. 254. Density of the Arnylic Salts of Glyceyic Acid. In the following table, we have collected the densities, calculated for equal temperatures, of the several amylic salts of glyceric acid described above ; the densities are referred to water at 4".GLYCERIC, DIACETYLGLYCERIC, ETC., ACIDS.269 From From From iiiactive acid. active acid. active acid. Teinp. act. alcohol, act. alcohol, iiiact. alcohol, Ainylic f 11" 1-0807 1.0797 1.081 1 Glycerates I. 47 1.0505 1,0495 1.0505 1.0863 1.0859 1.0855 1.0485 1.0468 1.0466 hmylic I :!j 1~0000 0.9985 0.9977 I>iacetylglycerates 1 1.1433 1-1456 1.1452 1.123'7 1.1236 1.1227 1.1049 1-1044 1.1032 1.0749 1.0746 1.0732 Amylic Dibenzoyl- gl ycerates 99.s The above figures show that the densities of the optical isomers are in each case in very close agreement. Conipa&on of the Anzylic Xcdts of Glyctwic Acid with those peuiously pepcwed. In order to compare the constants given above for the amylic salts with those of the derivatives previously prepared by one of us (Percy Frankland and MacGregor, Trans.1893, 63, 1415; 1894, 65, 754), it is necessary to calculate the densities to 15'/15', and the specific and molecular rotations, as well as the molecular deviations to 15". Thus, ~ Ethereal Salt Amylic Glycerates, from Active alcohol ...... Inactive acid ......} Active alcohol. ..... Active acid ......... } Inactive alcohol ... Active acid ...... ...) Amylic Diacetyl- glycemtcs, from Active alcohol ...... Active a1 coho1 ..... Inactive alcohol ...I Actire acid J Inactive acid ...... } Active acid ........ )' ......... Density 'Molecular 15"/'15" volume. Specific rotation a t 15" [.ID 1,0783 163.2 + 2-83' 1.0773 163'4 1.0786 163.2 I I 1,0834 I 240'0 1.0828 240.1 1.0824 240.2 - 11.55 - 14.12 f 1.67 - 17-44 - 19.44 - rIolecular rotation.M [ u ] D 100 + 4.98' - 20.33 - 24'85 + 4.34 - 45.31 - 50.54 Molecular deviation + 16.69" - 68 '05 - 83.20 + 1 1 2 4 - 117.4. - 130.8 Note.-In the above table, " active alcohol " =I=vo-amylic alcohol, ' - Product of asym- metry. P x 106 _I- 324.3 3 2 4 3 324.3 67'3 67 '3 67 '3 nactive - alcohol " = racemised ainylic alcohol (secondary butylcarbinol) ; (' active acid " = dextro-glyceric acid ; '' inactive acid " = (racemised) glyceric acid. VOL. LXXI. U270 FRANKLAND AND PRICE: THE AMYL DERIVATIVES OF Of the above compounds, the ones which can be directly compared with the previously prepared glycerates and diacetylglycerates are those obtained from the inactive (racemised) amylic alcohol.From the following table it will be seen how these derivatives of the inactive (racemised) amylic alcohol fall into line with the corresponding deriva- tives of the other alcohols hitherto examined by one of us. Ethei-eaZ X d t s of Active GZyce?-ic Acid. ' Methylic.. ....... 1.2798 Ethylic ......... 1.1921 Propylic ...... 1 '1448 Isopropylic.. .... 1'1303 Butylic (norm.) 1.1084 Isobutylic ...... 1'1051 Amylic (second- ary butylmc- thyl) ......... 1 *Of86 Heptylic(nor1n.) 1 -0390 Octylic (norm. ) 1'0263 Iolecrilar Differ volume. cn:e. 112'4 129'3 130.9 146'2 146.6: 163'2 196'3 21 2-4 93'8 1- 13 6 Specific rotation. h l [ a ] D1*jU - 4'80" - 9'18 - 12'94 - 11'82 - 13'19 - 14.23 - 14.12 - 11'30 - 10'22 IIoleculxl rotation, 100. RI - [.ID - E;.S@.J - 12'30 - 19'15 -17.49 - 21 -37 - 23'05 - 24 *a5 - 23 -05 - 22-25 Molecular deviation. a 3 - 1 0 6ID= +In' - 27'9" - i2.8 - 14'9 - 67'8 - 77.0 - 82'9 - 83'2 - 68.3 - 62'6 Nethylic......... Ethylic ......... Propylic ......... Isopropylic ...... Isobntylic ...... Ainylic (second- ary butylnic- thyl). ......... Octylic ......... Heptylic ......... EtJiei*eaZ &Its of Active DicccetyZgZyces.ic Acid. 1.1998 1'1574 1'1263 1'1193 1 '0990 1'0824 1.0537 1'0408 170*0} 188'4 206 .O \ 207.3) 223 ' 8 240'2) -- 24-56" - 35-56 - 45.17 - 41.69 - 50.38 - 50.54 - 47.89 - 47'92 - ao-oo - 105'2 .- 129.5 - 119'1 - 136.7 - 130.8 - 113'6 - 109'5 Prodnct of asym- metry. P x 106. 2sa-8 344.8 358'2 358'2 346.8 346.8 324.3 268'7 241 '8 0 0 17.4 17'4 4 1 '9 67'3 110'4 126'2 Note.--Product of' asginmetry for hexylic glycerate = 296'8.Y ? 9, ,, diacetylglycerate = 90.7. The results contained in the above table, and which are sore easily followed froin the curves in the appended diagrams (Figs. 4,5,6,) show t h a t (1) the density, in the case of the glycerntes, diminishes more rapidly with increasing molecular weight than is the case with the ciiacetylglycer;Ltes, and as was already pointed. out by one of us (Trans., 1593, 63, 1428) t h e curves should intersect between the butylic and amylic compounds. This is now actually found t o be the case, for whilst isobutylic glycerate has a greater density than isobutylioGLYCERIC, DIBCETYLGLYCERIC, ETC., ACIDS. 271 diacetylglycerate, the density of amylic glycerate is less than that of amylic diacetylglycerate.FIG. 4. -Densities of Ethereal Salts of Glyceric and Diacetylglyceric Acids (:;) . I *30 7 4 1-21 8 5 1.12 9 6 3 I * 00 (2) As has been already shown, both in the series of the glycerates and in that of the diacetylglycerates, there is a maximum rotation FIG. 5. --Molecular Volumes of Ethereal Salts of Glyceric and Diacetylglyceric Acids -o . (:r> 300 2 50 200 I50 100 50 300 250 200 I50 100 60 which occurs i n eacb case between the butylic and the heptylic com- pounds, the highest rotation in each series having hitherto been found for the butylic compound. The addition now of the amylic term to u 2272 FRANKLAND AND PRICE: THE AMYL DERIVATIVES OF each of these series becomes, therefore, of particular interest. The above figures show that in respect of specific rotation [a],, the maximum falls on the isobutyl term, both in the glycerate and in the diacetyl- glycerate series ; on the other hand, in respect of molecular rotation M# the maximum falls on the amyl term in both series, whilst in respect of molecular deviation [?)ID, it falls on the amyl term in the glycerate series, and on the isobutyl term in the diacetylglycerate series.The differences between these two terms are, however, com- FIG. 6.-Molecular Rotations [MID and Molecular Deviations [ 8]D of E'thereal Salts of Glyceric and Diacetylglyceric Acids, 15". 150" - 1 2 5 O -1000 -75O -50° -25' 0" paratively small, as the curves in this part are almost straight lines parallel to the horizontal axis. It should, however, be pointed out in this connection that, inasmuch as in the preparation of the amylic (inactive) glycerate (active) the excess alcohol recovered had a slight negative rotation (see p.265), it follows that the alcohol actually etherified must have had a slight positive rotation, and it must therefore be concluded that, had the C,H,, which entered the glyceric acid been quite inactive, the rotation of the amylic glycerate produced would have been slightly more nega- tive than it was found t o b& Thus the rotations given above for the amylic (inactive) glycerate (active) and the amylic (inactive) diacetyl- glycerate (active) are probably a little below the truth, in consequenceQLPCERIC, DIACETYLGLTCERIC, ETC., ACIDS, 273 of the slightly unequal etherification of the optical isomerides of which the inactive aniylic alcohol is composed.Of course, this remark is sub- ject to the reservation made on p. 265 with regard t o the apparent in- equality of the etherification. From their structure, it is obvious that the amyl compounds we have prepared are more directly comparable with the isopropyl and isobutyl compounds than with those of normal structure, and thus in the diagrams they have been treated as iso-amyl compounds. The Dibenxoyl Deyivcctives of Active Glyceric Acid.-In the following table we have compared the densities and rotations of the clibenzoyl derivatives of active glyceric acid, as far as we have yet prepared and studied them. Ethereal Salts of Active Dibenxoylglyceric Acid. Ethereal salt. ____~ ~ Methylic , Ethylic .... Propylic . Butylic ... . Amylic(in- active) ... Hexylic . Heptylic , Octylic . . . . 268'6 284'8 301.5 335.0 - - - - - 1'1574 1'1270 1.1067 1-0730 - - - - - 263.4 303-5 321-7 357'9 - - - - - +26%9 +26*58 +31'00 +16'31 - - - - - -- ___ +17'SO +SS.20 +lS.O.i +90-90 +14.20 +74.76 +I256 +70-31 - - - c - h c3 c: 0 Q.- G X PI " h 5 Q PI - 61.5 - 37.4 - 19'1 - i ' 3 - 1.2 f 0.4 - 1.4 - 5.j 2s B E -- - The above table shows, as already pointed ont by one of us (Trans., 1894, 65, 758; 1896, 69, 104), that the introduction of the two benzoyl groups reverses the sign of the rotation, all the dibenzoyl- glyceratea having a positive, whilst the glycerates, diacetylglycerates, dipropionylglycerates, and diphenacetylglycerates have a negative rotation. The tendency of the positive rotation in this series of dibenzoylglycerates is obviously t o diminish as the magnitude of t'he alkyl radicle increases.There is, however, a slight departure from this general tendency apparent in the case of the methyl and ethyl corn- pounds, as it would be anticipated that the positive rotation of the methyl should be considerably in excess of that of the ethyl compound, whilst, as a matter of fact, the specific rotations of these two compounds was found to be almost exactly equal over a wide range of temperature. At first sight, it might be suggested that the rotation of the methyl compound is abnormally low, owing t o its forming molecular aggregates (the methyl compound melts at 58-59', the ethyl a t 25"), but a t higher temperatures, which should lead t o the breaking up of such aggregates, the rotation of the ethyl compound is more distinctly in274 FRANKLAND AND PRICE: THE AMYL DERIVATIVES, ETC.excess of that of the methyl compound. The general relationship of the rotations in this series, excluding this anomaly in the case of the first term, indicates that the lavo-rotation conditioned by the alkyl- group tends to counteract the dextro-rotation which is conditioned by the benzoyl-groups; thus, in the simple glycerates, as has been shown above, the laevo-rotation increases from the methyl to the amyl com- pound, the same is the case in the diacetylglycerate series, whilst in this dibenzoylglycerate series the positive rotation diminishes from the methyl to the amyl compound. Just as, therefore, in the glycerate and diacetylglycerate series, the negative rotation passes through a ntnxinzum at the bntyl or smyl compound, so in this dibenzoylglycerate series, it is t o be anticipated that the positive rotation will pass through a rnininzu.ri2 a t the same terms of the series.Thus we should expect that the heptylic and octylic dibenzoylglycerates would have a greater positive rotation than the amyl-compound. It remains to be seen whether a furthur study of the higher members of this interesting series will confirm this prediction. The ' product of asymmetry,' as seen from the above table, also predicts such a minimum at the hoxyl term, with the noticeable feature that the sign of the product of asym- metry actually changes for the hexyl-compound, changing back again for the heptyl and higher terms of the series. The further study of these compounds will, therefore, be attended with special interest. h&ueme of Tempemtwe o n the Rotation of the Arnylic Xcclts aj Glyce~ic Acid. Attention has repeatedly been drawn by one of us to the influence of temperature on the rotation of optically active organic compounds, and the active compounds described in this paper exhibit some interesting points in this connection. 1. The rotation of the amylic salts of active diacetylglyceric acid and of active dibenzoylglyceric acid is very sensitive to temperature, whilst that of the amylic salts of the corresponding inactive acids is insens- itive to temperature, showing, therefore, t'hat the sensitiveness is dependent on the active acid radicle, 2. The rotation of all the simple amylic glycerates, amylic (active) glycerate (active), nmylic (active) glycerate (inactive), and amylic (inactive) glycerate (active) is insensitive to temperature. It has been shown in a previous paper (Trans., 1894, 65, 769), that the rotation of methylic glycerate is more sensitive to temperature than that of ethylic glycerate, and it thus appears that in the series of the glycerates, as f a r as it has been yet investigated, as the alkyl radicle increases in magnitude the sensitiveness of the rotation to temperature diminishes.BROWN, MOBIUS AND MILTAAR : THE SOLUTION-DENSITY, ETC. 275 3. The sensitiveness of the diacetylglycerates has been more fully investigated (Zoc. cit.), with the result that i t was found to diminish with the increase in the magnitude of the alkyl radicle as far as the isobutyl compound, the rotation of the heptyl and octyl being slightly more sensitive than that of the isobutyl compound. The sensitiveness of the rotation of amylic (inactive) djacetylglycerate (active) is now found to be exactly the same as that of the isobutyl compound. These two compounds have also nearly the same specific rotation. It would thus appear that the sensitiveness attains a. minimum in those ternis of the series in wliich the actual rotatlion reaches a maximum, or in which the addition of CH, produces the least effect on the rotation. Throughout the glycerates and diacetylglycerates, the negative rotation increases with rise of temperature. 4. In the dibenzoylglycerate series, the positive rotation diminishes with rise of temperature. I n this series, again, the sensitiveness of the rotation diminishes in passing from the methyl to the amyl com- pound. XASON COLLEGE, 'BIRNINGHAM.

ISSN:0368-1645    

DOI:10.1039/CT8977100253

出版商:RSC    

年代:1897

数据来源: RSC

摘要:

BROWN, MORRIS AND MILTAAR : THE SOLUTION-DENSITY, ETC. 275 XX I I. - The So 1 yc t i o j ~ - dens it y a jzcl Ciip~ic- yedir c in 9 Power of Dextrose, Lcvulose, and Ikce rt-suguir-. By HORACE T. BROWN, F.R.S., G. HARRIS MORRIS, Ph.D., and J. €I. MILLAR. The Xolutio./2-clensities. IN a previous communication (Trans., 1897, '71, p. 72), we have entered fully into the necessity for the accurate determination of the solution- densities of the carbohydrates, in order that the correct factors for the estimation of the solid matter in carbohydrate solutions may be de- duced. I n the paper above referred to, we gave the results of the accurate determination of the solution-densities and divisors for various concentrations of maltose, soluble-starch, and the products of the con- version of starch by diastase.We have now carried out a series of similar determinations for dext,rose, levulose, and invert-sugar. The apparatus used for drying the respective sugars was that described in our former paper (this vol., p. 76). I n this, crystallised dextrose can be rendered perfectly dry in 4 hours at 105-106" without the slightest decomposition or coloration taking place. Crystallised levulose can be dried still more readily, but the operation requires greater care, on account of the low melting point of this sugar. The temperature of the bath must not be allowed to rise27G BROWN, MORRIS, AND MILLAR : THE SOLUTION-DENSITY AND above 75" for the first three or four hours, but after that it may rise to 85-90'. The latter temperature must not be exceeded, or the substance fuses and begins to colour.A total period of 6 hours a t the given temperatures is amply sufficient to drive off all moisture without the slightest discoloration taking place. The sugars used in the experiments were prepared with the greatest possible care by the most approved methods, and were repeatedly recrystallised from alcohol u n ti1 their properties were absolutely con- stant. The dextrose was prepared from three sources, namely, from pure maltose by acid hydrolysis ; from cane-sugar by inversion with acid, and from a crystallised sample of dextrose obtained from Kahl- baum. The levulose mas prepared in two mays, the one from inulin in the manner described by Wohl (Bey., 1890, 23, 2107), and the other from a sample of Schering's crystallised product.Invert-sugar was obtained by the inversion of pure, crystallised cane-sugar with yeast, asd in some experiments, by mixing equal quantities of perfectly pure dextrose and levulose. I n the results given in the following tables, Column a gives the weight of dry substance taken, Column b gives the total weight of solution. Column c gives the specific gravity of the solution at 15.5", referred Column cl gives grams of sugar per 100 C.C. (reputed)". Column e gives the divisor for the determination of grams per 100 to water at 15.5". C.U. (reputed) from the specific gravity. Fuble I.-Solution-density of dnhydrous Dextrose. I a. - ' I 1 '2988 1-6324 3'2659 3.2751 8'3380 6'4414 9'0925 6. C. 49.8518 30'5690 51'2638 31'1712 53'7774 36 '5604 8 9 '9196 1010*12 1020.95 1025.07 1041 -94 1062.93 1072.03 1094 -6 6 d.2.6317 5-4516 6'5306 10 -9 470 16 '4800 18.8870 24'9330 1 3'845 3'842 3.839 3.831 3.818 3.813 3'796 The above results are expressed graphically in the dextrose curve of Plate I. (p. 278),* and the true divisor for any pat ticular concen- tration can be obtained by inspection of this curve, or from the following equation, in which D is the required divisor, and G the specific gravity of the solution when water = 1000. D = 3.848 - 0*00028 (G - 1000) - 0.0000028 (G - 1000)2. * For the meaning of this expression see this vol., 1,. 77, footnote,CUPRIC-REDUCING POWER OF DEXTROSE, LEVULOSE, ETC. 2'7'7 The divisors for dextrose deduced from the foregoing experiments agree very closely with those recently given by C.O'Sullivan and Stern (Trans., 1896, 69, 1695). Y'a6Ze II.-SoZution-density of Anhydrous Levdose. - 1 2 3 4 5 6 7 8 - n. 1'2326 3.1436 2.5962 2'0306 6'5677 4'8289 5'0967 7'0191 1). 50 %868 51.3029 40'7573 27 *5 29 4 54.0685 38 '6 4 76 32 *5304 34 '0 505 1009'72 1024.67 1025'65 1029'67 1049 -85 1051 -35 1065'06 1 OSi '10 d . 2.4676 6.2784 6.5330 7'5576 12.7530 13'1360 16.6870 22'4000 e. 3'939 3'929 3'926 3'925 3'909 3'909 3-898 3 '886 The foregoing results are embodied in the levdose curve on Plate I., the equation for which is D =' 3.946 - 0.00068 (G - 1000) - 0~0000007 (G - 1000)2. We have already fully discussed (Zoc. cit.) the relation of the divisor we have hitherto employed (3.86) to the true divisors for the carbo- hydrates, and it is, therefore, unnecessary t o again refer to the matter, We may, however, point out that here, as in the cases we have pre- viously given, the divisor decreases as the concentration of the solution increases.So far as levulose is concerned, this is in direct opposition to the results obtained by Hijnig and Jesser (Moncctshefte, 1888,9,562), from which it appears that the divisor increases with the concentration. Since it has been conclusively shown that invert-sugar is a mixture of equal amounts of dextrose and levulose, we calculated from the fore- going results the divisor to be applied to solutions of invert-sugar. This was done by taking the mean of the divisors for dextrose and levulose for solutions of one-half the gravity of that of the invert-sugar solu- tions; thus, the divisors for dextrose and levulose for a solution of sp.gr. 1010 are 3.845 and 3.939 respectively; the mean of these is 3.892, which was taken as the divisor for a solution of invert-sugar of sp. gr. 1020. W e are aware that this is not quite correct, as solutions of the same specific gravity do not contain exactly equal amounts of dextrose and levulose, and, moreover, no allowance is made for the lower solution- density of the solution of double strength; but the error thus introduced is so small, being in the fourth place of decimals, that it fa119 well within the limits of experimental error. In this way, we obtained the following table.278 RROWN, MORRIS, AND NILLAR : THE SOLUTION-DENSITY AND Gravity. I/ Gravity. 1 Divisor. Divisor. 1 I I I 1010 1020 1030 1040 1050 1060 3.894 3.892 3.889 3.886 3-883 3-8813 1070 1080 1090 1100 1110 1120 3.817 3.874 3.871 3.868 3'865 3.862 The foregoing values mere checked at several points by determinations made with pure invert-sugar, and were found to be correct.They are expressed graphically in the invert-sugar curve of Plate I, the equation for which is D = 3.897 - 0*00025 (G - 1000) - 0*0000004 (G - 1000)'. The Czqwic-yeducing Powem. I n the paper already mentioned (Zoc. cit., p. 95, et sep.), we discussed, a t considerable length, the conditions requisite for the accurate and concordant determination of the cupric-reduction of the carbohydrates, but it mill be advisable to briefly recapitulate them here. They are (1) the use of a Fehling's solution of constant composition; (2) the maintenance of the same degree of dilution in all experiments ; (3) the precipitation of an amount of copper oxide which shall fall between certain limits ; and (4) an invariable method of determination, both as regards mode and time of heating.The composition of the Fehling's solution me use is Recrystallised copper sulphate . . . Rochelle salt ... . .. ... .. . ... .. . .. . ., . 173.0 ,, 9 ) Anhydrous sodium hydroxide . . . 65.0 ), ? ? 34.6 grams per litre. Fifty C.C. of this solution, which should be freshly mixed, are placed in a beaker of about 250 C.C. capacity and having a diameter of 7.5 centi- metres. This is placed in a boiling water bath, and when the solution has attained the temperature of the water, the accurately weighed or measured volume of the sugar solution is added, and the whole made up to 100 C.C.with boiling distilled water. The beaker, which is covered with a clock glass, is then returned to the water bath, and the heating continued for exactly 12 minutes. The precipitated cuprous oxide is now rapidly filtered off through a Soxhlet tube, mashed first with hot water, then with alcohol and ether, and finally dried. When dry, the cuprous oxide is reduced to metallic copper by gentle heating in a stream of hydrogen, and weighed. The weight of copper obtained must be cor- rected for that due t o the slight spontaneous reduction which alwaysBROWN, MORRIS, AND MILLAR. Journ. Chern. SOC. Xarch, 1897. PLATE IBROWN MORRIS AND MILLAR. J o u m , Cham, sbc, Naroh, 1897CUPRLC-REDUCING POWER OF DEXTROSE, LEVULOSE, ETC.279 takes place, and which should be determined for each batch of Fehling’s solution. Working in this way, we have determined with great care the cupric- reducing power of dextrose, levulose, and invert-sugar, taking in each series of experiments gradually increasing amounts of the sugar, and determining the copper reduced by each amount. The results are em- bodied in the following tables, which are given in the same form as those in our previous paper, to which reference has been made. The sugars used were prepared as indicated in the first part of this paper, and were most carefully and thoroughly purified. I n the dextrose table, the source from which the sugar mas obtained is indicated in the first column ; the determinat’ions marked cc were made with dextrose prepared from Kahlbaum’s product ; 6, from maltose, by acid hydrolysis; and c, from cane-sugar, by inversion with acid.Tcc 6 Ze I V.-C~~~”’ic-1.ecluctiosa of Dextisose. - Sonrcc. b CL c C b CL C c 6 C6 c 0 CL c 6 Dextrose by 3-86 divisor. 0-0457 0.0474 0’0491 0.0736 0’0884 0’0950 0.0980 0 1180 0-1338 0’1425 0.1555 0.1786 0‘1911 0’1968 0’2105 Dextrose tlbsolute. 0,0459 0.0476 0.0493 0.0739 0.0888 0.0954 0-09P4 0.1185 0.1344 0.1431 0.1592 0.1793 0.1919 0.1976 0.2114 CU weighed. 0’0938 0.0983 0’1024 0.1513 0.1809 0.1963 0’1996 0’2369 0.2648 0.2836 0’3089 03397 0.3635 0.3732 0.3920 CUO )er gram of 3-88 lexc,rose. 2572 2599 2’614 2 5 7 7 2-564 2 5 7 7 2.553 2’516 2‘480 2.494 2.442 2.385 2.384 2.377 2.334 CUO ier gram of absolute lextrose.2.562 2.589 2’604 2.567 2,554 2.567 2543 2507 2.470 2.485 2-433 2.375 2.375 2.365 2.325 116’6 117’9 118’5 116’8 116’3 116‘8 115-8 114.1 112.4 113‘1 110.7 108’1 308’1 107.8 105.8 - fCnbnnll1 tr. 116’2 118‘1 116’3 115.8 116‘4 115.3 113.7 112’0 112.7 110’3 107.7 107.7 107.4 105.4 11 7.4 The above results are expressed graphically in curve I of Plate I1 (p. 280), which shows that the copper oxide reduced by 1 gram of dex- trose appreciably decreases as the amount of copper reduced increases,280 BROWN, MORRIS, AND MILLAR : THE SOLUTION-DENSITY AND Levulose by 3-86 divisor. 0-0403 0.0443 0.0446 0-0473 0'0507 0-0964 0.0964 0.0964 0.0964 0'1455 0-1443 0'1438 0.1890 0'2011 0.2022 0'2043 Fable V.-Cup.ic-reduction of Levulose. Levulose absolute, 0.0396 0'0466 0'0500 0'0949 0'0949 0'0949 0.'09 4 9 0'1432 0'1421 0'1416 0'1861 0'1980 0'1991 0'0435 0'0438 0.2012 - cu weighed.0.0750 0.0822 0.0831 0.0887 0.0939 0.1765 0-1765 0.1770 0.1787 0.2612 0'2601 0'2585 0'3290 0.3507 0.3526 0'3576 - - cue per gram of 3.86 levulose. 2.329 2'323 2.332 2'323 2.318 2.295 2 9 9 5 2.301 2'324 2.251 2.260 2-254 2.182 2.186 6.186 2.194 - cue per grain of absolute levnlose. 2.375 2'369 2'379 2.360 2 -355 2'332 2-332 2'338 2'361 2-287 2.295 2.289 2'217 2.221 2'220 2.228 - 105'6 105.3 105'7 105-4 105-2 104'1 104.1 104.4 105'3 102.1 102.4 10272 99 .o 99 -2 99.2 99.5 Kabsolote. 107.7 107'4 107.9 107'0 10673 105.7 105.7 106.0 107.0 103'7 104.0 103 '8 100.5 100-7 100-7 101.0 7 From the foregoing numbers, curve I11 of Plate I1 has been con- structed. It will be seen that, throughout the series, any given amount of levulose reduces appreciably less copper than the same weight of dextrose.Tu, 6 Ze V1.- Ctcpic-reduction of Invei*t -sugar. Invert- sugar by 3.86 divisor. 0 *0506 0.0860 0.1095 0-1303 0'1582 0'1847 0.2167 Invei.t-sugar absolute. c 11 weighed. 0,0502 0-0854 0.1087 0 1293 0.1570 0.1833 0.2152 0,0979 0.1681 0.2085 0.2511 0.2965 0.3386 0.3890 ' CUO per grain of 3'86 invert- sugar. 2'426 2'449 2'387 2.416 2'350 2.298 2'250 CUO per gram if absolute invert- sugar. 2.445 2-468 2.405 2.435 2-368 2.316 2'267 110.0 110.9 111'0 111'9 108-2 109.0 109'5 110'4 106'5 107'4 104.2 105'0 102.0 102.8 The above results are expressed graphically in the invert-sugar curve I1 of Plate 11, which falls midway between the curves for dextrose and levulose.From the curves obtained when the foregoing experimental results are plotted on a system of rectangular co-ordinates, we have con- structed the folIowing table showing the reducing powers of the threeCUPRIC-REDUCING POWER OF DEXTROSE, LEVULOSE, ETC. 281 I 2 3 I rR - 5c 5E: 6C 6: 7c 75 8C 85 90 95 1 oc 105 115 120 125 130 135 140 145 150 155 160 165 170 176 180 185 190 195 200 205 i i a - sugars in question. We have given, in the first column, the quantities of sugar from 50 to 205 milligrams, at intervals of 5 milligrams, and, opposite to these, the amounts of Cu and CuO precipitated by each quantity, together with the weight of CiiO corresponding to 1 gram of each sugar, when the respective quantities are oxidiaed under the conditions of our method.Cn grams. 0'103C 0.1134 0 '1 23€ 0 '1 341 0'1543 0'1644 0.1740 0'1834 0.193a 0'2123 0.2218 0'2313 0.2404 0.2496 0.2585 0.2675 0.2762 0.2850 0.2934 0.3020 0.3103 0.3187 0.3268 0.3350 0.3431 0-3508 0 '3590 0'3668 0'3745 0.3822 0'1443 0'2027 - Dextrose. CLlO grams. 0'1289 0'1422 0.1552 0'1682 0.1809 0-1935 0.2061 0'2187 0.2299 0.2420 0.2538 0'2662 0.2781 0.2900 0'3014 0,3130 0'3241 0'3354 0'3463 0.3573 0'3673 0.3787 0.3891 0.3996 0'4098 0'4200 0'4302 0'4399 0.4501 0.4599 0'4689 0'4792 Ell a . GE 9 @ u 2 0 o+ 2'578 2'585 2'587 2.589 2.585 2'580 2.577 2'572 2'555 2'547 2'538 2'535 2'528 2'522 2'512 2'504 2'493 2'484 2'473 2'464 2'448 2'443 2'432 2'428 2'410 2-400 2'390 2.377 2.369 2.358 2.344 2.338 c Ll grams. 0'0923 0.1027 0.1122 0'1216 0'1312 0.1405 0.1500 0.1590 0'1686 0,1774 0'1862 0'1952 0.2040 0.2129 0 *2215 0'2303 0'2390 0'2477 0'2559 0'2641 0'2723 0.2805 0,2889 0'2972 0'3053 0.3134 0.3216 0.3297 0.3377 0'3457 0.3539 0'3616 Levnlose.cuo grams. 0.1155 0.1287 0.1407 0 -1 524 0.1645 0'1761 0.1881 0'1993 0.2114 0 '2224 0.2331 02447 0.2558 0.2669 0-2777 0.2887 0.2997 0.3106 0.3209 0.3311 0.3409 0.3517 0.3622 0.3726 0.3828 0.3930 0.4032 0.4134 0.4234 0 ~ ~ 4 3 3 5 0'4431 0 '4534 2.310 2'341 2.345 2'346 2-350 2 *349 2.351 2'346 2 '349 2.341 2.331 2-331 2.325 2'321 2'314 2'310 2.305 2'300 2'292 2'284 2.273 2 '269 2'264 2'258 2-252 2-245 2'240 2-234 2'228 2'223 2.216 2-211 - c 11 grams. 0.0975 0'1076 0.1176 0.1275 0-1373 0 '1 468 0-1566 0.1662 0.1755 0.1848 0'1941 0.2034 0'2128 0,2220 0.2311 0'2400 0.2489 0-2578 0'2663 0.2750 0.2832 0.2915 0.3002 0'3086 0'3167 0-3251 0.3331 0'3410 0'3490 0.3570 0.3650 0,3726 - Invert -sugar.CUO grams. 0'1221 0.1349 0'1474 0'1598 0'1721 0'1840 0'1963 0'2084 0'2200 0'2317 0.2430 0'2550 0 '2668 0.2783 0'2898 0.3009 0.3121 0.3232 0-3339 0.3448 0.3546 0.3665 0.3764 0-3869 0'3971 0.4076 0.4177 0.4276 0.4376 0.4476 3'4570 3'4672 - 2 '442 2'453 2'457 2.469 2.459 2'454 2.454 2.451 2'445 2'439 2 '430 2'429 2'425 2'420 2'415 2'407 2-400 2 '394 2.385 2'378 2'364 2.358 2.352 2.345 2'336 2.329 2.320 2'311 2.303 2.295 2'285 2.279 - Before commenting on our results, it will be necessary to refer briefly to the method at present in use of expressing the cupric-reducing power of the sugars. I n 1876, C. O'Sullivan (Trans., 1876, ii, 125),282 BROWN, MORRIS, AND MILLAH : THE SOLUTION-DENSITY AND defined this ‘‘ to be the amount of cupric oxide, calculated as dextrose, which 100 parts reduce.” The cupric rednction of dextrose mould then be 100, and 1 gram of this sugar was considered to reduce 2.205 grams of copper oxide.O’Sullivan expressed this value by K, and the symbol K had previously been used by one of us and Heron (Trans., 1879, 35, 607) with the same significance. It has long been known that the 2.205 value for dextrose was not quite correct, being, in fact, too low, and consequently that the true cnpric-reduction of dextrose was distinctly above 100 when referred to this standard. As we have, however, already pointed out a t length, i n the paper previously referred to (this vol., p.97), this is immaterial if it is clearly and definitely understood to what basis the cupric-reducing power is referred. From the foregoing experiments with dextrose, it will be seen that we have obtained considerably higher values than those mentioned above. We find that the amount of copper oxide reduced by 1 gram of the sugar ranges from 2.562 to 2,325 grams, according to the extent to which reduction of the Fehling’s solution is carried; and on the- 2.205 basis, these numbers correspond to a K of 116.2 and 105.4 respectively. Recently, and after our experiments were finished, Heron (Journal Federated Irzstitutes Bvewing, 1896, 2, 443) and C. O’Sullivan and Stern (Trans., 1896,69, 1691) pointed out the higher reducing power of dextrose. The former states that 1 gram reduces 2.26 grams of cupric oxide, but he does not mention the precise conditions under which this value was obtained.The latter authors give 2,306 grams of CuO as the equivalent of 1 gram of sugar, and the mean reducing value as K = 104.6 ; they use 30 C.C. of Fehling’s solu- tion diluted to a t least 90 c.c., and take from 0.12 t o 0.13 gram of sugar. Under these conditions, me should expect that their results mould be somewhat lower than ours. The method employed by Kjeldahl in his investigations on the cupric- reduction of the sugars (R6mnzti du Compte-rerzdzc des travaw du bboratoire du Carlsberg, 4’”” vol., 1’”. livr., 1895), very closely resembles ours, with the exception that the Fehling’s solution is heated for 20 minutes, and the reduction carried on in an atmosphere of hydrogen.As would be expectedfrom this variation in the conditions, his values for the cupric-reduction of dextrose are uniformly higher than ours ; but the difference is fairly constant throughout the series. This, we have already shown, was also the case with maltose (loc. cit.). It has always been generally held that the reducing powers of levulose and invert-sugar were less than that of dextrose. This fact is well shown in the foregoing results, and also in Table VII., which gives the amount of copper oxide reduced by 1 gram of each sugar at different stages of reduction. It has been stated by J. O’SullivanCYUPRIC-REDUCING POWER O F DEXTROSE, LEVULOSE, ETC. 283 (Trans., 1892, 61, 408) and by Heron (Zoc. cit.) that the reducing power of invert-sugar is the same as that of dextrose, but this is nega- tived by our results, which are, on this point, in accord with those of Kjeldahl (Zoc.cit,), Ost (Ber., 1850, 23, 3003), Honig and Jesser (Moi~atsliefte, 1888, 9, 562), Soxhlet (J. pr. Chem., 1880, 21, 227), and other workers. The results obtained by these workers, although not exactly the same as ours, owing to the differing conditions of experiment, yet show that levulose has an appreciably lower reducing power than dextrose, and that the cupric-reduction of invert-sugar stands inter- mediate between the two. If we take the results expressed in Table VII, and calculate from them, at certain points, the cupric-reducing power, K, expressed on the old basis of 2.205, we get the following values for the three sugars.Milligraiiis Dextrose Levulose Invert-sugar Sugar. K. K. K. 50 116-9 104.7 110.7 100 115.1 105.7 110.2 150 111.0 103.1 107.2 200 106.3 100.1 103.6 If, however, we take the value of dextrose a t each of the above points as 100, and express the values of levulose and invert-sugar as percentages on this number, we get the following results. Milligrams Sugar. Dextrose. Levulose. Invert-sugar, 50 100 89-60 94-72 100 100 01.s4 05.74 150 100 92.s5 96.56 200 100 04.1 1 97-05 We see, then, from these numbers, that if the reducing power of dextrose be taken as 100, when what may be regarded as the usual amount of copper is reduced (150 to 200 milligrams), the values to be assigned to levdose and invert-sugar closely approximate to those which have been usually taken for these sugars.I n our former paper, t o which reference has repeatedly been made, we showed the great influence which the amount and nature of the alkali in the Fehling’s solution exercised on the quantity of copper reduced by a given weight of maltose, or of the starch-transformation products. With dextrose and levulose, the influence is far less. Kjeldahl has shown (loc. cit.), and we have confirmed the observation, that the amount of sodium hydroxide per litre may be varied within fairly-wide limits, without producing any considerable alteration in the amount of copper reduced by a given weight of dextrose; whilst284 BROWN, MORRIS, AND MILLAR : THE SOLUTION-DENSITY, ETC. - 105.0 104.1 101.9 101.0 - I Glendinning has proved (Trans., 1895, 6’7, 999) that an equivalent amount of potassium hydroxide may be substituted for the sodium compound without causing any alteration in the reducing power. The variant which has the greatest influence in the case of dextrose and levulose is the state of dilution of the Fehling’s solution.If the 50 C.C. of Fehling’s solution is diluted with 100 c.c., 150 c.c., or 200 C.C. of water, instead of with the 50 C.C. of our standard method, the reducing power is appreciably lower at all stages of reduction, and the greater the dilution, the greater the difference. This is well seen in the following table, in which the results are given in terms of K absolute. Thble QII1.--Reducing Poww of Dextvose and Levulose at di$ere?Lt Degrees of Dilution. - - 102.6 102.9 102-2 101 ‘9 100‘9 99 -8 99.7 98 *9 - - - - Sugar grams. I Dextrose. Dilution 1 :2. 0.0725 0.0846 0‘1120 0.12’15 0.1 697 0.1830 0.1901 116.7 114.6 - - - 108.1 - Dilution 1 :3. 115.2 113’9 107’8 - - - - Dilution 1 :4. 113.0 111.8 - - - 107.2 - Levulose, Dilution Dilution Dilution 1 : 2 . I 1 : 3 . 1 1:4. I The degree of dilution has, however, a much greater influence on the reducing power if the experiments are made in a different manner, namely, by keeping the total volume of solution constant, and decreas- ing the amount of Fehling’s solution in such volume, Kjeldahl made a series of experiments in this way, using 15, 30, 50, and 75 C.C. respectively of Fehling’s solution and making up the volume in each case to 100 C.C. When nearly the maximum amount of copper was precipitated from the more dilute solutions, much lower values than those given above were obtained for the cupric-reducing powers, and we have confirmed these observations by direct experiment. In our former paper (this vol., p. 106), w e fully discussed the limits of error of the methods employed for the determination of solution density and cupric-reducing power, and they, therefore, need not be recapitulated here,

ISSN:0368-1645    

DOI:10.1039/CT8977100275

出版商:RSC    

年代:1897

数据来源: RSC

摘要:

MARSH AND GARDNER : RESEARCHES ON THE TERPENES. 285 XXII I.-Reseawhes on the Teypeues, VII. Huloqcn Berivutives of Camphor uizd thew Reactions. By J. E. MARSH and J. A. GARDNER. IN 1882, De la Roykre (Bull. Xoc. Chem., 38,579) described a compound of the formula C,,H,,Br,, which he obtained by the action of phos- phorus trichloride and bromine on camphor. He subsequently showed (BUZZ. Acad. Bely., 9, 565, 10, 759) that two isomeric compounds were obtained, both capable of forming, by loss of HBr, one and the same tribromocamphene, C,,H,,Br,. We had begun to study the action of phosphorus trichloride and bromine on camphor and on various members of the turpene group in ignorance of the work of De la Roykre, and it will be seen that the results which we have obtained in the case of camphor confirm those of the Belgian chemist, differing from his only in points of detail.Action of Phospho~us Tvicl&ride and Bromine on Camphor. The quantities taken were such as to correspond approximately with the equation C,,H,,O + Pc'l, + 3Br, = CloH,,Br4 + POCl, + 2HBr. The phosphorus trichloride and bromine were mixed in chloroform solution, and the camphor added gradually, the whole being kept cool. A t first, a red, crystalline compound is formed, possibly C,,H,,OBr,, which gradually disappears, hydrogen bromide being evolved, and the liquid becoming nearly colourless after a few days. It is then poured on ice, and the chloroform solution, separated from the aqueous liquid, is allowed to evaporate, The crystalline product, which is readily soluble in chloro- form, is dissolved in hot, light petroleum, in which it is only sparingly soluble and, on cooling, the greater part, consisting of the a-compound, crystallises out.It melts at 1 6 8 O , and forms small, fluffy crystals. On evaporating the mother liquor a t the ordinary temperature, the P-modi- fication crystallises out in large transparent plates melting at 1 4 4 O , along with small crystals of the a-compound, from which it can be sepa- rated mechanically. Occasionally, the two forms crystallise together in the form of round, crystalline nodules, apparently homogeneous, and melting about 120" ; they may, however, be sepamted by recrystallisa- tion and mechanical selection of the two kinds as before. The yield is good, although a quantity of oily matter is also formed, which we were unable t o crystallise.a-Trib*omocamp?tene hydrobromide.-This crystallises from light petro- leum in the form of a white powder ; it is much more readily soluble in chloroform, and on evaporation is deposited in large, hard, colourless VOL. LXXI. X286 MARSH AND GABDNER: RESEARCHES ON THE TERPENES. crystals melting at 168". It is dextro-rotatory, [a], = + 90.3" in chloro- form solution. On analysis, it gave the following percentage composition. Carbon. Hydrogen. Bromine. Total. Found. ................. 26.24 3.14 70.46 99-84 Calculated C,oH,,Br, 26.43 3.08 70.48 99.99 fl- 25.ibro?~~ocr~rn;vkere hydi-obromide, -This compound, which is formed in much smaller quantity than the other, crystallises from petroleum in large, transparent crystals melting a t 143-144".It also is dextro- rotatory, but much less so than the a-compound. In cbloroform solu- tion, it gave [ = + 7%". The following are the results of analysis. Carbon. Hydrogen. Bromine. Total. Found.. ................ 26.59 3-24 70.34 100.17 Calculated C,,H,,Br4 26.43 3.08 70.48 99.99 Action of Ylt,osphorzcs Trichloride and Bvonaine o n Borneo 1. Borneo1 was treated in the same way as camphor, the substances being taken in the proportion of 4 mols. of bromine to 1 of borneol and 1 of phosphorus trichloride. Much hydrogen bromide was evolved, and the product, after treatment with water, gave crystals from a mixture of alcohol and chloroform melting a t 166-168". They were recrystal- lised from light petroleum. It gave [a], = + 91" in chloroform solution. Calcnlated Found.C,,H,,Br4. Bromine ........................ 70.68 70.48 The crystals were thus identical with the a-compound obtained from camphor. It should be mentioned that the melting point of the a-compound varies according to the conditions under which the sub- stance is heated. If it is heated very slowly, it melts a t 168", decom- posing a t the same time ; but if it is heated rapidly, the temperature a a y reach 173" before the substance melts. It would appear that 168" is the temperature a t which the compound begins t o decompose, rather than its actual melting point. The action of phosphorus trichloride and bromine on menthone and on fenchone has been investigated, but liquid products only were obtained. On a-brornocamphor of m.p. 76", there is only a slight action, with the production of a compound probably identical with a-tribromocamphene hydrobromide.HALOGEN DERIVATIVES OF CAMPHOR AND THEIR REACTIONS. 287 Action o f Phosphorus TmkJdoride and &*ornine on Tu? pentine. Dextrorotatory turpentine was subjected to the action of bromine and phosphorus trichloride in chloroform solution. Thirty grams of the turpentine, 30 of phosphorus trichloride, and 76 of bromine were em ployed. After treatment with ice, an oil mas obtained which was dis- solved in light petroleum, and alcohol added so as to form two layers. Crystals were obtained which were recrystallised from n mixture of chloroform and alcohol. They form colourless needles melting a t 150". Found ..................19-34 2.52 78.18 100*04 Carbon. Hydrogen. Bromine. Total. Calculated CloHl,Br, 19.54 2-28 78-18 100*00 The action of phosphorus triohloride and bromine was tried on camphene and on turpentine hydrobromide, but liquid products alone were obtained. The action in the case of d-turpentine was very slow, and the yield of crystals small, only 4-5 grams of pure substance being obtained from the 30 grams of d-turpentine taken. All the bromine was used up, but the quantity employed was not sufficient to form a hexa- bromide, as it was not expected that this substance would be formed. T~ibi.onaoccL.~Lne, CloK,,Br3. When a-tribromocamphene hydrobromide from camphor is boiled for several hours with sodium methoxide, it loses hydrogen bromide and forms tribromocamphene.This can be purified by distillation in steam, when it comes over slowly ; if not distilled with steam, it is apt to be coloured yellow. Tribromocamp hene crystallises in long needles from alcohol ; it also crystallises well from ether and from ethylic acetate. It is very soluble in chloroform, and is left on evaporation of this solvent as a porcelain-like mass. It melts a t 75-76', and its specific rotation in chloroform solution is [a] = + 32.5" Carbon. Hydrogen. Bromine. Found ..................... 32.15 3.73 64.29 Calculated CloH,,Br, ... 32.17 3-48 64.34 The /3-tribromocamphene hydrobromide yields the same tribromo- camphene when treated in the same way with sodium methoxide. The specimen obtained from the P-compound melted at 75-76", and its specific rotation in chloroform solution was [a], = + 31.5".The production of the same tribromocamphene from two isomeric tetrabromo-compounds leads us to infer that, in the latter, three of the bromine atoms occupy the same position in the two isomers, and that the isomerism depends on the position of the fourth. The tribromo- camphene is a saturated compound. It neither absorbs bromine nor decolorises permanganate. x 2288 MARSH AND GARDNER: RESEARCHES ON THE TERPENES. Action of Phosphorus Pentacldos-ide on Camphor. Camphor was treated with about 18 times its weight of pentachlo- ride of phosphorus, using Spitzer's method, the whole being kept cool. The camphor slowly liquefies, and the pentachloride gradually goes into solution with slight evolution of hydrogen chloride.After seven or eight days, the mass was treat,ed with ice, care being taken that, during the decomposition of the oxychloride of phosphorus, the temperature should not rise, as, if this happens, a considerable decom- position occurs, and the product of the action is profoundly altered, becoming dark coloured and partly liquid. By operating in the cold, however, a white, solid product is obtained ; this, according to Spitzer, after purifying by crystallisation from ether, is camphene dichloride, a substance melting at 155". By treatment with light petroleum, how- ever, it is possible to separate the original substance into two, one very soluble in petroleum and separating on evaporation in small crystals which aggregate into masses, the other scarcely soluble in petroleum in the cold, but crystallising from the hot solvent in large, hard, transparent crystals.The amount of the latter product is variable, but in two experi- ment's about 35 per cent. of the weight of the camphor was obtained ; it is not improbable, however, that it may reach 5G per cent., the excess remaining dissolved in the petroleum. We call this compound a-chlo~o- cccmphne hyhochloYide, and the one more soluble in petroleum P-chloro- camphem hydrocldoride. a-CIdorocamphene hyclrocl~lmide. -This compound, as stated above, is left as a white, crystalline powder sparingly soluble in cold, light petro- leum; from the hot solvent, it separates in hard, large, transparent crystals melting at 165" with decomposition, and having the rotatory power [u) = - 2'7.7" in chloroform solution.This substance also crys- tallises well from alcohol in similar hard, distinct, crystals which show no tendency to aggregation. It does not give off hydrogen chloride on keeping ; at looo, it slowly evaporates. Carbon. Hydrogen. Chlorine. Total. Pound ..... ... ......... 58.0 8.1 34.3 100.4 Calculated C,,H,,CI, 58.0 7.7 34.3 100.0 P-Cldorocamphene hydrochZoride.-It is not certain that this sub- stance has at present been obtained free from the a-modification, and we are still engaged in investigating it. I t forms the part more soluble in light petroleum, and is left, on evaporating the solvent, as a white, adherent, crystalline mass. It crystallises well from alcohol, and these crystals also adhere to one another when dry, and stick to glass and paper.It slowly loses hydrogen chloride when kept, so that a bottle containing it, after standing for some time, smells of the gas ; in this, itHALOGEN DERIVATIVES OF CAMPHOR AND THEIR REACTIONS. 289 resembles Spitzer's compound. Its rotatory power is less than that of the a-compound. The value [a]= = - 13%" has been found in chloro- form solution; in one specimen, however, the rotation was as low as - 9". Chlwocc~mphem, C,,H,,Cl. a-Chlorocamphene hydrochloride (I 0 grams), prepared from camphor, was boiled for several hours with zinc dust (7 grams) and glacial acetic acid. On distilling in steam, a solid of low melting point came over which was taken up by ether and distilled. It boiled at about 202" and solidified in the receiver. Its rotation was taken in chloroform solution [a] = - 29.3".The chlorine was determined. It gave, Found. Calculated C,oH,,Cl. Chlorine ..................... 20.7 20.8 P-Chlorocamphene hydrochloride, treated in the same way with zinc and acetic acid, yielded a product which distilled for the most part at about 205", but the temperature rose to 220" before all had come over. The distillate, which was solid, was again treated with zinc and glacial acetic acid, and finally a product obtained which distilled between 199" and 201". It was a solid of low melting point, and gave the specific rota- tion in chloroform solution [ a = - 33.2". A determination of chlorine gave Found. Calculated CloHl,C1. Chlorine ..................... 20.2 20.8 The chlorocamphene thus obtained acts as a saturated compound ; it does not decolorise permanganate of potash at the ordinary tempera- ture, and is acted on by bromine with evolution of hydrogen bromide.It is not improbable that the chlorocamphenes from the a- and @hydrochlorides are identical, but we have not been able finally to establish this point. There seems little doubt that Pfaundler (Anna- Zen, 1860, 115, 36) previously obtained chlorocsmphene, but was wrong in attributing its formation to the proportions of camphor and penta- chloride of phosphorus taken; this must be attributed rather to his having heated the mixture, and thereby decomposed a portion of the dichloride of camphene into chlorocamphene and hydrogen chloride. Spitzer ( A m d e n , 1879, 196, 260) was unable to obtain chlorocam- phene in a pure state by Pfaundler's method, nor did his camphor dichloride yield chlorocamphene when heated with water, or with water and marble, or with aniline at 110" (Sitxungsbe?*. Akad.TVGn, 1880, 596). We had made several experiments on the dichloride ob- tained by Spitzer's method, with a view to the production of chloro- camphene, before we found that this dichloride was a mixture ; our ex- periments show, however, that although the dichloride readily loses some290 MARSH AND GARDNER: RESEARCHES ON THE TERPENES. of its hydrogen chloride, it is difficult to remove the whole so as t o form monochlorocamphene. Not unfrequently, the product obtained gave an amount of chlorine just midway between the monochloride and the dichloride, as Spitzer himself found.For instance, the dichloride (34 grams), mixed with aniline (30 grams), was boiled for half an hour; after the aniline had been removed, the solid product contained 27.5 per cent. of chlorine, distilled between 205" and 230", and had a rota- tory power in chloroform of [a],= - 27.0". Some of the dichloride, after being boiled with aniline, was separated and heated in a sealed tube with quinoline at 250" ; when the product was distilled after removal of the quinoline, the greater portion passed over between 198" and 200°, and became solid. It gave 20.5 per cent. chlorine (calculated for C,,HI,Cl, 20-S), and its specific rota- tion in a mixture of alcohol and chloroform was [.ID = - 5". It was found that the dichloride, when distilled by itself, lost hydro- gen chloride, and that its rotatory power increased with each successive distillation.Thus, a specimen of the dichloride having the specific rotation [ a ] D = - go, when distilled, gave off hydrogen chloride, the boil- ing point rising to about 225" ; this distillate had the specific rotation [ a ] , = - 19" in chloroform. After a second distillation, the specific rotatory power rose to [ a ] , , -- - 30" in chloroform, and after a third dis- tillation to -35". The distillate was now crystallised from alcohol, and the crystals gave 23 per cent. of chlorine. Another quantity of dichloride distilled in a current of hydrogen chloride did not show this increase of rotatory power. After three distillations in a current of the gas, the distillate, after crystallisation from alcohol, had the specific rotation [ a ] D = - 7.7" in chloroform, and contained 31.1 per cent.of chlorine. Hydmxycccnzphe.e, 01' Camphenol. Chlorocamphene (p. 289) is very stable under the action of the usual reagents employed to replace chlorine or to remove hydrogen chloride. Thus, we found that quinoline at 250" did not remove hydrogen chloride. Moreover, when chlorocamphene is heated with potassium acetate and glacial acetic acid a t 220°, it is recovered apparently quite unchanged. Chlorocamphene, however, dissolves in cold, sulphuric acid, giving off torrents of hydrogen chloride and forming an orange-red liquid, a sub- stance being produced from the chlorocamphene by replacement of the C1 atom by OH. There is a certain quantity of tarry matter produced at the same time, but the yield is very good if the sulphuric acid has been previously diluted with about 5 per cent.of water, and if care be taken to keep the mass cool when the sulphuric acid solution is after- wards diluted with water.HBLOGEN DERIVATIVES OF CAMPHOR AND THEIR REACTIOXS. 291 The process adopted is as follows : Chlorocamphene (34 grams) was added to strong sulphuric acid (340 grams) previously diluted with 5 per cent. of water ; the action was brisk, much hydrogen chloride being evolved, with frothing. The red liquid was then poured into excess of water, and distilled with steam, about 20 grams of oil being obtained in the distillate. This mas extracted with ether, distilled, the distillate dissolved in sulphuric acid containing 10 per cent.of water, and the solution shaken with light petroleum, ot remove any chloro-compound or other impurity not dissolved in the sulphuric acid. The acid solution was again diluted with water, distilled with steam, and the oil, which is lighter than water, was extracted with ether and distilled. range of lo", the boiling point being at about 230". A number of analyses were made of different specimens of hydroxy- camphene, which, however, were found still to contain traces of chlorine, nearly 1 per cent. being found in one specimen, This chlorine does not appear to be removed by the action of sulphuric acid, and is probably due to the presence of some higher chlorinated substance in the chlorocamphene used, as chlorocamphene carefully puri6ed by frequent fractionation was found to yield hydroxycamphene quite free from chlorine. I.gives the analyses of 5 specimens of hydroxycamphene, all of which contained traces of chlorine. 11. Analysis of hydroxy- camphene free from chlorine. It all came over within Calculated Found. Ci0H160* Carbon ......... 78.3 78.5 78.0 77.8 77.5 78.9 Hydrogen ...... 10.3 10.2 10.5 10.4 10.8 10.5 Calculated Found. C10H160* Carbon .................... 78.7 78.9 Hydrogen 10.7 10.5 11. { ................ Hydroxycamphene, or camphenol, is a colourless liquid which becomes slightly yellow on standing. It has a fragrant, camphorous smell, and burning, aromatic taste. It boils at about 230°, and the density CL is d 18.5"/18*5" = 0.9347." It is insoluble in water, but dissolves ap- parently unaltered in strong sulphuric acid, in strong nitric acid, and in a saturated solution of hydrogen chloride in water.Bromine acts on it with evolution of hydrogen bromide. Sodium attacks it with evolution of gas and formation of a solid compound. Acetyl chloride does not act readily on the substance when cold, but on boiling it with benzoyl chloride, hydrogen chloride is evolved in abundance ; phosphorus pentachloride also acts violently with evolution of hydro- gen chloride. When acted on by potassium dichromate and dilute * The specimen used contained traces of chlorine.292 MARSH AND GARDNER: RESEARCHES Oh’ THE TERPENES. sulphuric acid, part of the substance is destroyed, but a large part is recovered unchanged. There is no evidence of the formation of a ketone in this reaction.We are still engaged in the further study of this compound ; we may, however, put forward the opinion that, taking into account the various properties of the substame, there seems no donbt that it is an alcohol, most probably a tertiary alcohol and a saturated compound. Nomenclccture. I n giving names to the compounds described in this paper, we have considered them as derivatives of camphene. This seems t o be the simplest mode of regarding them, and the most suitable for purposes of nomenclature. Moreover, camphene itself is derived from cam- phor in a way similar to that by which these compounds are them- selves derived, and for the sake of simplicity, as well as from the point of view of general analogy, this method of nomenclature appears to be the most suitable.Conclwion. The views which we have put forward from time to time as to the constitution of camphor and of camphene appear to us to be supported by the facts ,described in this paper. We bave insisted on the saturated character of camphene as well as on that of camphor. J u s t as we have camphene derived from camphor through bornyl chloride, so we have a saturated tribromo-compound and a saturated monochloro- compound derived from camphor in a very similar way. We have, in a previous paper, endeavoured to explain the relationship of camphene to camphor, and the saturated character of each of them, by the assumption of the existence of two ring formations in camphor and of not less than three ring formations in camphene, the mutual con- version of compounds of one class into those of the other being effected by the making or breaking of a ring formation.The nature of the compounds can hardly be reconciled with formuls for camphor, such, for example, as those proposed by Bredt and by Tiemann, formulae which, as we have already pointed out, do not seem to us to be sustained even by the evidence brought forward by their supporters. Besides the saturated character of camphene, we have, in particular, the production of one and the same tribromocamphene from two different tetrabromides, and probably the production of the same monochlorocamphene from two different dichlorides, and, further, the production of an isomeride of camphor from chloro- camphene. Tn the latter instance, we should have expected, from Bredt’s formula, to have obtained, not an isomer of camphor, but cam- phor itself.HALOGEN DERIVATIVES OF CAMPHOR AND THEIR REACTIONS.293 We append to this paper notes on the crystallographic characters of some of the cry&& kindly contributed by Prof. Miers and Mr. H. L. Bowman. CHEMICAL LABORATORY, OXFORD. UNIVERSITY MUSEUM, C R Y S T A L LO a R A P H I C DET E R M I N A T I o NS. BY PROF. MIERS AND MR. H. L. BOWMAN. a- Fribvomocamphene Hydrobromide (Crystccllised fiom Ether). System anorthic- Axial angles a = Z 12'22'. p= 114'58'. y = 73'18'. Axial ratios, cb : b : c = 1.1135 : 1 : 1.0189. Observed forms, P{100}, e(010), g{OOl), h ( i f l } , n{llO}, a{Oii}, 1(430}, m(410) ? FIG. 1. a-Tribromocamphene hydrobromide crystallised from ether. Angles.Pe 1OO:OlO ge 001 :010 Pg 100:001 ~h ioo : iii eh oio : Ti1 Pn 100 : lL0 Pa 100 : 011 PI 100 :430 ga 001 : o i l Pm 100 : 410 1 Observed. 98"42&' 72"38' 69'19g 69'55' 61'37' 53'334' 64'1 5' 34'55' 53"4' l7"40' Limits. 98'28'-98'57' 72'25'-73"5' 69'9' -69'27' 69'33'-70"18' 61 "1 8'-61'5 6' 53'3 3'-53"34' 63'35'--64"57' - - - No. of edges. 7 5 11 8 3 2 3 1 1 1 Calculated. - ._ - - - 52'15' 64'8' 34'45' 51'46' 15'42'294 MARSH AND GARDNER: RESEARCHES ON THE TERPENES, 56'299' 35'46' 65'22' 70"12$' 55"4' Traces were seen of a face on the edge between (100) and (001) making an angle of about 55;" with (100) ; also of a face on the edge between (010) and (110) making an angle of about 33" with (010). The crystals were extremely imperfect, and variable in habit ; some appeared to be twinned, the plane of union being parallel to IL (iil), and the crystal being traversed by a lamina parallel to that face.Birefringence strong ; an optic axis emerges obliquely through P (loo), the plane containing the optic axis and the normal to P being nearly parallel to the edge Ph. 56'29'-56'30' 35'43'-35"54' 6 5'20'-65 "24' /3-Tribs.omocccrnphenne Hydsdwornide. System orthorhombic- Observed forms, cc(lOO), bfOlO), m{110), 7-{01l},f{102), x{120}, x may possibly be hemihedrally developed, appearing sometimes at cc : b : G = 0.7203 : 1 : 0.6621. only one end of the brachydiagonal a. FIG. 2. B-Tribromocamphene hydrobromide, 111. p. 144". br 010:011 am 100 : 110 af 100:102 wzf 110 : 102 ax 100:120 0 bserved. Limits. No. of edges. Calculated.I - - 65'25' 70'16' 55'14' Optic axial plane (001) ; acute bisectrix perpendicular to the face Optic axial angle, as measured through a natural crystal immersed The crystals are tabular owing to the large development of the (010). Birefringence strong, negative. in cedar oil, was found to be 53"45' for sodium light. faces (100).HALOGEN DERIVATIVES OF CAMPHOR AND THEIR REACTIONS. 295 ~ ~ 3 2 110 : i i o 88 011 :011 ST 011 : l o 1 ms 110:011 T~ibs.oll~ocuin2~lene (csystallised fq-orn dcohol). By s t em or t h orhom bic- CL : b : C = 1.0410 : 1 : 0.6164. Observed forms, m2(110}, s{Oll}, ~f101). a7"42' 87"7' -88"4' 6 63"ia' 63'15'-63'22' 3 1 42'57' - 67'45' 67"42'-67"48' 2 F I G . 3. Tribromocamphene crystallised from alcohol. Angles. Observed. l l Limits. No.of edges. Calculated. - - 42'549' 67"46' Optic axial plane (001). An optic axis emerges through each face rn, and at an inclination of 6" to the normal of nz, on the side towards the crystallographic axis b. Birefringence very strong ; the bisectrix which coincides with the crystallographic axis b is negative. The crystals from which the above results were obtained are acicular, the substance having been crystallised from alcohol. When crystallised from ether, the crystals were of quite different habit, being tabular, owing to increase of two opposite faces m. Some other faces occurred, possibly of the forms (120) and (2211, but these were too rough to give trustworthy measurements.296 MAltSH AKD GARDNER: RESEARCHES ON THE TERPENES. I;C-C'hlo,~ocanaphene Hychochlo?*itle. System or t ho rhombi c -- Observed forms, nfl@@), b{010), mfllO}, still), ~ ( O l l ) , x(lOl), cc : b : c = 0.9169 : 1 : 0.5906. q{ 223;. FIG. 4. a-Chlorocamphene hydrochloride. ~ Angles. 7nb 110:010 llLS 110 : 111 712a 110 :lo0 222s 110 : iii bs 010:l~l ss 111:ill ss 111:111 9mn 110 : 110 snr 11O:Oll 7nq 110:223 br 01O:Oll Observed. 47"29' 48'51' 42'334' 63'34' 51'40' [ 57"53'] 85'2' 86048' Limits. 47"22'-47"36' 48'42'-49'5' 42"15'--42"55' - - - - a4°50~--850ii~ - :75:31 [ 59"45']-[59"47'] 59'184' I 59'15'--59'22' No. of edges. 25 9 11 1 1 1 K1 [I1 23 2 2alculated. - - 42'31' 86'44' 63'36' 52'48' 58'2' 69'54' 59'26' 8502' 59'46.4' Measurements inclosed in square brackets were only made by means of the Optic axial plane (010). A negative bisectrix perpendicular to (OOl), Birefringence strong. The faces (100) are usually narrow. The face (111) is much smaller than (171). The face (223)q may possibly occur hemihedrally, since it mas, in more than one instance, developed on one corner of the crystal done. These crystals appear to be identical in form, though not in habit, with those described by F. v. Spitzer (Berichte Akad. Wien, 1880, 71, p. 596). maxinium illumination of the faces. the optic axes visible through (001) making a wide angle. MINERALOGICAL DEPARTMENT, UNIVEESITY MUSEUM, OXFORD.

ISSN:0368-1645    

DOI:10.1039/CT8977100285

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年代:1897

数据来源: RSC

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JAPP : SUPPOSED CONDENSATION OF BENZIL WITH ALCOHOL. 297 XXIV.-Supposed Conderisation of Bend with Ethylic Alcohol. A Correction. BY FRANCIS ROBERT JAPP, F.R.S. I FIND that the compound described by me, in a paper published jointly with Miss Owens (Trans., 1885, 47, go), as formed by the condensa- tion of b e n d with ethylic alcohol, is in reality identical with Japp and Miller's a.nh~d?.acetonedibe.laxil, C,,H,,O, (m. p. 194-1 95"), and that its formation was due to the presence of acetone in the '' methyl- ated spirit '' (alcohol '' denatured '' with 10 per cent. of crude wood spirit)," which was used instead of duty-paid alcohol in its preparation. We found it necessary to use an enormous excess of spirit in the re- action, and attributed thia to the fact that, with more concentrated solutions, the caustic potash, which we employed as a condensing agent, converts the benzil into benzilic acid; but the true explanation is that this large excess of spirit was required to furnish the requisite amount of the active impurity, acetone.The formula, C30H2404, which we ascribed to the condensation com- pound, requires figures differing only very slightly from those required by anhydraeetonedibenzil. I n the case of the percentages of the various '' solvents of crystallisation "-alcohol, benzene, and acetic acid-which we determined, the differences are smaller still. At the time the paper was published, we believed the compound to be identical with Limpricht and Schwanert's ethy?dibenzo'in, C,,H,,O,, which Jena was supposed to have obtained by the action of alcoholic potash on benzil, the reaction employed by us.On the strength of this belief, we proposed t o alter Limpricht and Schwanert's formula to C30H2404, and we further cast doubt on the existence of an acetyl derivative which these investigator8 had described. I need not say that I greatly regret the publication of these per- fectly baseless criticisms on Limpricht and Schwanert's work. I am indebted to Professor Alexander Smith, of the University of Chicago, for privately informing me that he had not succeeded in pre- paring the compound from benzil and alcohol, and thus calling my attention to the matter. CHEMICAL DEPARTMENT, UNIVERSITY OF ABERDEEN. * For the benefit of foreign abstmctors, the term '' methylated spirit " should always be defined when used ; failing which, I find that they invariably confound this substance with methylic alcohol. Thua in the Juhrmberieht for 1887, p. 954, the abstract of a paper of mine is rendered quite nnintelligible by this blunder.

ISSN:0368-1645    

DOI:10.1039/CT8977100297

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年代:1897

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298 LIVERSIDGE: PRESENCE OF GOLD IN NATURAL SALINE, ETC. XXV.-Presence of Gold in Natural Saline Deposits and Hayine Pluiz ts. BY A. LIVERSIDGE, LL.D., F.R.S., Professor of Chemistry in the University of Sydney. THE experiments referred to in this paper were made in 1895 in connection with an investigation into the presence of gold and silver in sea water *; but as the work has had to be laid aside for a time, the present paper may be regarded as a preliminary one. Amongst the substances already examined for gold are rock salt, sylvine, and other similar mineral substances, also bittern, the ashes of seaweeds, kelp, oyster shells, &c., all of which were found to contain both gold and silver ; the amounts of silver will be given in a subsequent paper. The process used for determining the amount of gold was to dissolve from 100 to 1000 grams of the salt in water, then to add, without previous filtration (since the gold may be wholly or in part i n suspen- sion), from 0.5 to 5.0 grams of ferrous sulphate, and allow the latter to oxidise slowly by exposure to the air or by drawing air through the mixture; the precipitate produced was then scorified with lead free from gold, and cupelled, or, to hasten the experiments, the iron hy- droxides were precipitated by the addition of a little ammonia.This process, as shown in one of the previous papers above referred to, does not throw down all the gold, so that the results are understated : later on, I hope to repeat the determinations by other and more efficient processes. My principal reason for examining the saline minerals was because gold occurs insea water, and it is not unnatural to expect its presence in salts deposited from sea and other waters ; further, as I had found that fungoid growths removed gold from suspension and from solution,? I thought that seaweeds and other marine organisms might show an accumulation of gold.This I found to be the case. Amongst the results are the following. Rock Salt, Cheshire 1.7 grains of gold per ton, ,? 9 , red ,> 1.49 ,, 9 ) 9 7 ,, ,, ,, Stassfurth 2.03 ,, 9 , ,? Table Salt . . . . none ,, 7, 9 7 * (1) ‘‘ On the Amount of Gold and Silver in Sen Water.” Jozmn. Boy.. Soc. (2) “011 the Removal of Gold a i d Silver from Sea Water by t. ‘‘ On the Removal of Gold from Suspension and Solution by Fungoid Growths,” N.8.TV., 1895. Muntz Metal Sheathing,” ibid. ; see also Chem. iVews, 1896, 74, 182. Report A d . Assoc. Adv. Science, 1890.COLLIE : PRODUCTION OF PYRIDINE DERIVdTIVES, ETC. 299 Sylvine . . . . , 1.1 grains of gold per ton. Deposit from Salt pan 1.3 ,, Y f 9 9 Kainite , . . . . 1-96 ,, 9 9 9 , Carnallite . . . . 1.2 ,, 7 9 9 9 Chilian nitre . . . 1.69 ,, 7 ) 9 7 As might be expectec?, bittern yielded larger quantities of gold than sen water; one specimen gave 5.08 grains t o the ton whilst another gave as much as 14 grains, but as it was a very old specimen of unknown origin, this result requires confirmation. One specimen of kelp was also found to contain no less t h a n 22 grains of gold to the ton, but as the specimen was also very old and of unknown origin, this result must be confirmed, and I think it desirable to compare the results with those from other kelps.If, however, the sample be a fair one, then I think that the suggestion which I threw out in a previous paper, that it might pay to extract gold as a bye-product in the manufacture of salt, iodine, &c., will, perhaps, be justified. During the next year, I hope to examine further samples of bittern and kelp of both European and Australian origin. It would be extremely interesting to examine the mud and other deposits from salt pans or salterns ; especially from some of the old ones like those of Lymington, which have been used from Roman times, where, if the conditions have been favourable for the retention of the gold, we might find quite noticeable quantities of the precious metal. Another investigation which ought to be undertaken is to determine the amount of gold and silver in various minerals and rocks by more delicate processes than those used in assaying both in auriferous and non-auriferous districts, as it is one which could probably throw much light on the origin of gold in veins and similar deposits. Processes such as are described in the paper on the presence of gold in sea water should be used, inasmuch as the ordinary methods of assay are not sufficiently delicate.

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DOI:10.1039/CT8977100298

出版商:RSC    

年代:1897

数据来源: RSC

摘要:

COLLIE : PRODUCTION OF PYRIDINE DERIVdTIVES, ETC. 299 XXVI.-Production of Pyridine Derivatives from Ethylic p- Amidowotonctte. By J. NORXAN COLLIE, Ph.D., F.R.S. AMONGST compounds from which pyridine derivatives can be obtained, ethylic acetoacetate stands out prominently, and since Hantzsch (Ann., 1882, 215,lO) showed that, by warming this compound with aldehyde- ammonia, die thylic dihydrocollidinecarboxylate was formed, almost every year has seen some addition to the ever-increasing number of300 COLLIE : PRODUCTION OF PYRIDINE DERIVATIVES FROM closed ring nitrogen compounds which can be produced either from ethylic acetoacetate or its condensation derivatives. I have already called attention to the fact that when ethylic /3-amido- crotonate is destructively distilled, various pyridine derivatives are formed (AWL, 1884,226,297; Trans., 1891,59,172 ; also Trans., 1895, 6'7, 2 15), the chief product being ethylic lut3donemonocarboxylate. I have also shown how pyridine derivatives could be produced by the same kind of reaction from dehydracetic acid and from triacetic lactone, both condensation products of ethylic acetoacetate.Some years ago, during attempts to obtain larger quantities of ethylic lutidonemonocarboxylate, I prepared the hydrochloride of ethylic /3-amidocrotonate in the hope that, when it was heated, it would con- dense at a lower temperature, according to the following equation: C6H,,N0,,HC1 + C,H,,NO, = C,oH,3N0, + NH,CI+ C,H,* OH. The re- action took place at once, and a large quantity of a pyridine com- pound was obtained, but I was astonished to find that, not only was the product of the action a mixture of two substances, but that they both had the formula C,,H,,NO,, and also that they were both entirely distinct in properties from ethylic lutidonemonocarboxylate ; their melting points were as follows.Ethylic lutidonemono- Compound A. Compound R. carboxyla te. A short note of the reaction was published in 1887 (Bey., 20, 445), and, since then, from time to time I have investigated the properties of these two substances and their compounds. They are both ethylic salts, and yield alcohol and the sodium salts of acids when warmed with caustic soda solution. 138-139"" 166-167" 163-164" The melting points of the acids are- Lutidonemono- Compound A. Compound B. carboxylic acid. 300-304" 190-1 91 " 254-256" When heated above their melting points, they both decompose quanti- tatively into pseudolutidostyril, a substance first obtained by Hantzsch (Bey., 1884, 17, 2904).Now Iutidonemonocarboxylic acid, when heated, yields lutidone, \CO/ Lutidone. CH3 Pseudolutidostyril. * All the melting and boiling points given have been determined by means of ti set of Auchutz thermometers, and are therefore corrected temperatures.ETHYLIC P-AMIDOCROTONATE, 301 and as both the acids from compounds A and B gave pseudolutido- styril, it seemed possible that the difference between thein might lie in some stereochemical molecular arrangement. After furthur study of their properties, however, I have abandoned this idea, as it is quite possible t o explain their various differences and the produehion of pseudolutidostyril by ordinary graphic formula The interesting fact still remains that, if ethylic P-amidocrotonate is heated alone, it yields lutidone derivatives, whilst its hydrochloride yields two isomeric coni- pounds which are derivatives of pseudolutidostyril. The formation of these two compounds may be explained as follows.C:OOEt* CiHNH,j-C(CH,)=CH -+ COOEt. 8 C(CH,):CH' , ..................... CH,* C-NHiH 1 1 ; ............. :,.. ................... EtO'-~O ! CH; C *NH- 70 i HCI; ! ............. I Etb ylic B-amidocrot ona t e Compound A, in. p. 138-139 hydrochloride. or eth ylic pseudolutidostyril monocarboxylate. whilst the tnutomeric modification of ethylic P-amidocrotonate would give COOEt.CH,*C=NjH I ...., EtO\-- ............... .... . COOEt*CH, Q: N--- 8 OH yo += HC:C( CH,) * CH Compound €3, ni. 1'. 166-167". ............, HCiH,NH'I-C(CH,). CH, ; HC1: Ethylic B-imidobutyrate, ................. This reaction is precisely similar to that which takes place when ethylic 1utidonemonocarboxylate is formed (compare Trans., 1895, 67, 401), when dehydracetic acid is heated with strong ammonia, or when dehy- dracetic acid is produced by the distillation of ethylic acetoacetate. The production of pseudolutidostyril from the free acids of either of the two compounds A. and B is easily accounted for- ,;COO;H-CH,.F '. ....... . _ I Yo \ c HCH ........ ........... HC Yo C 3-1 I ',COO:HC I /NH\ /NH\ ........ CH C. I coo H-cH,*$ CH, Acid A. CH3 Acid 8. These compounds are, therefore, derivatives of isodeh ydracetic acid, /O\ CH,E yo COOHC CH ; VOL.LXXI. Y302 COLLIE : PRODUCTION OF PYRIDINE DERIVATIVES FROM the connection of that acid with pseudolutidostyril was first pointed out by Hantzsch (Ann., 1884, 222, 46). A great deal of the work that has been done with these nitrogen compounds has been with the object of attempting to arrive possibly a t reactions by which it mould be possible to follow, step by step, the formation of true pyridine compounds. These oxy-derivatives are hardly true pyridine derivatives, being almost devoid of basic pro- perties, but yet are as closely allied to pyridine as phloroglucinol is to benzene. When treated with chlorinating agents, they give chloro-deri- vatives which, without doubt, contain the atomic linking present in pyridine itself.One is, therefore, able to follow the gradual change from an open chain compound, such as ethylic P-amidocrotonate, through a series of reactions, none of which need a high temperature, until, finally, true pyridine derivatives are obtained. These oxypyridine compounds, therefore, supply excellent material for the investigation. From their formation and properties, the evidence seems to be more in favour of the linking in the pyridine ring resembling that of benzene, than that it should be represented by the formula suggested first by Lieben and Haitinger. For, although the formation of y-chlorolutidine by treating lutidone with phosphorus pentachloride seems to favour Lieben and Haitinger’s formula, \ C O / Lutidone.\ d d y -Chlorolutidine. still the production of a-chlorolutidine from pseudolutidostyril is in direct opposition to such an atomic grouping, A CH,*S YCl HC CH FH\. + CH,. yo HC CH Pseudolutid OR tyril. a-Chlorolutidine. The explanation which agrees best with all these reactions is that the internal linking of the pyridine ring resembles that of benzene, and therefore it may be expressed either by the original formula for pyridine that Karner first suggested, or by what is practically identical with it, the centric formula,ETHYLIC 6-AMIDOCROTONATE. 303 d ctioit @' Heat on the Hydi*ochlos.icle of' Ethplic P-Amidocrotomte. When perfectly dry hydrogen chloride is passed into a dry ethereal solution of ethylic P-amidocrotonate, a precipitate begins t o form almost at once, and settles to the bottom of the flask as a semi-crystal- line mass.This crystalline compound is at once decomposed by water into ammonium chloride and ethylic acetoacetate, but if collected carefully and analysed, it is found to contain 21.6 per cent. C1, 43.4 per cent. C, and 7.5 per cent, H. C,H,,NO,,HCl requires 22.3 per cent. C1, 43.5 per cent. C, and 7.3 per cent. H. When the crystals are heated they partially melt, and an action a t once occurs with evolution of heat, the mass becoming almost solid from separation of ammonium chloride, By treating the product with a small quantity of water, the ammonium chloride can be washed away, leaving a solid, crystalline residue, which dissolves almost entirely in boiling water ; after filtering from the small quantity of undissolved resinous matter, the filtrate, 'on cooling, sets to an almost solid mass of long, silky needles When purified by several recry stallisations from hot water, the compound melts a t 138-139".The mean of a large number of analyses gave the following result, c. H, N. Found ... . . . . . .. . . . . .. . . . . , . . , 61.6 6.9 7.3 Calculated for C,,H,,NO:~ . . , 61.5 6.6 7-2 The molecular weight was determined by the Rrtoult method, using Found, 194. R1.W. of C,,H,,WO, = 195. The reaction, therefore, occurs according to the equntioii As hydrogen chloride mas evolved during the action, it was thought, that time might be saved by only half-saturating the ethylic P-amido- crotonate with the gas. An experiment was made, using 100 grams of the amidocrotonate dissolved in ether, the solution being divided into two equal portions, one of which was treated with excess of gaseous hydrogen chloride, the other half added, and the ether evaporated off on a water bath.The flask was now transferred to an oil bath and heated t o 120°, when a vigorous reactmion occurred; on cooling, the contents of the flask were treated with a small quantity of water t o remove ammonium chloride, and the residue recrystallised from water, These crystals mere found to be very different from those obtained before; nltimately they proved to be a mixture of two com- pounds, one, A, melting a t 138-139", the other, B, melting a t 166-167" (the chief product). acetic acid as the solvent. BC,H,,NO.,,HCl = C1,,H1,KO;, + CPHR* OH + NH,Cl + HC1.Y 2304 COLLIE : PRODUCTION OF PYRIDINE DERIVATIVES FROM The new compound, B, was anslysed; the mean of several analyses gave, C. H. N. Found . . . , . , . . . . . , . . . . . . . . . . . . . . . 6.8 7.4 Calculated for C,,H,,NO, . . . 61 -5 6.6 7.2 The molecular weight was determined by tbe Raoult method, using glacial acetic acid as the solvent. Found, 195. C,,H,,NO, requires From these analyses, it appears that the compounds A and B are isomeric, and at first it seemed that the change in the conditions of the experiment had determined the formation of the new compound, and that the semi-saturation of the amidocrotonate with hydrogen chloride was the reason for the production of B. This, however, was not found to be the case, for, on attempting to prepare compound A, using crude benzene (b.p. 80-120")instead of ether, and fully saturating with hydrogen chloride, the compound B again seemed to be the chief product. This, however, was not always the case, for in another experi- ment with benzene, A was formed in considerably larger quantities than in the first trial; ultimately, after many different methods had been tried, it was found that, if the solvent used was evaporated off at a low temperature, so as t o leave the hydrochloride in a pure condition, then, on further heating to a temperature of about 120", compound A alone was produced, whereas, if crude benzene was used or excess of amido- crotonate, a varying mixture of A and B was the result. The yield of either of these compounds was never as much as 50 per cent., much resin being always formed at the same time.I n one experi- ment, 400 grams of pure amidocrotonate was saturated with hydrogen chloride in ethereal solution, and 140 grams of A was obtained; whilst, in another experiment, 200 grams that had been semi-saturated with the gas gave 60 grams of B mixed with 5 grams of A. Compound A is easily purified by recrystallisation, but compound B is more difficult to separate from the resin formed a t the same time; of the two, A is also the least soluble in water. Sometimes the separation was effected by warming with dilute solution of soda for a few minutes ; under these conditions, B was a t once hydrolysed, whilst A remained undecomposed, and crystallised out again on cooling the solution.The acid, of which B is the ethylic salt, was recovered by acidifying the soda solution. To sum up,-(1) When 100 grams of ethylic P-amidocrotonate was dissolved in ether, and saturated with dry gaseous hydrogen chloride, and the ether evaporated, the residue, on heating, gave 30 grams of A melting at 138-139". (2) When 100 gram? of ethylic pamido- crotonate was semi-saturated with the gas and heated under similar conditions, 25 grams of €3 was obtained mixed with small quantities of A ; the yield of B, however, often varied in different experiments, 61.8 M.W. = 195.ETHYLIC P-AMIDOCROTONATE. 305 The theoretical amount that ought to be produced is '71 grams, the yield, therefore, is only 40 per cent. Of the various experiments tried, it may be mentioned that B was also produced in small quantities when ethylic P-amidocrotonate was treated with acetyl chloride.Both A and B are ethereal salts of acids, and yield alcohol and a sodium salt when boiled with caustic soda. But A has to be per- sistently boiled with strong soda solution before the decomposition is complete, whilst B, as has been already mentioned, is hydrolysed at once. Many attempts were made to convert the one into the other, but boiling with acids, heating with water alone in sealed tubes, or with acid did not effect the change. The compound A crystallises from hot water in long silky needles, but these become granular by stirring or standing when it is quite pure, and settle down to a thin layer at the bottom of the crystallising vessel. When boiled with acetyl chloride, no change occurs, and the substance may be heated with acetic anhydride at 140" for 6 hours with no result.Hydroxylamine does not seem t o form any compound, and nitrous acid or boiling hydrochloric acid is without action on it. If it is heated a t 100" with strong sulphuric acid and the mixture then poured into water, the unchanged compound separates out again. The action of heated soda lime was also tried. 10 grams was mixed with and distilled over excess of heated soda lime; traces of ammonia were produced, but the chief product was an oil boiling at 280-285". This gave a well crystallised platinochloride, containing no water of crystallisation ; the mean of four analyses gave 25.9 per cent, Pt. When the compound A is dissolved in glacial acetic acid, and bromine is added in excess, a bromine compound is produced which can be preci- pitated by pouring the mixture into water; it recrystallises from alcohol in long, glistening needles, melts a t 158-159', and on analysis proved t9 be a monobromo-substitution product.The mean of several analyses gave C = 44.0 ; H = 4.5 ; N = 5.3 ; Br = 29.1. Calc. for CioHl,NO,Br : C = 43.8 ; H = 4.4 ; N = 5-1 ; Br = 29.2. Compound A also reacts with pentachloride of phosphorus. It is best not to dilute the substance with any solvent, but to add the penta- chloride in small quantities, keeping the flask heated in an oil bath a t 180". Theory for (C,HI,NO),,H,PtC1 is 26.2 per cent, The reaction is as follows :- CioH1,NO, + PCI, = C1,H12N02C1 + POCI, + HCI. The action is not violent, and after the oxychloride of phosphorus has been distilled off, the residue can be added to water and steam distilled.The oil which passes over when purified boils at 288-290" Its analyses gave the following numbers, C = 56.6; H = 6.0306 CO1,LIE : PRODUCTION OF PYRIDINE DERIVATIVES z;"I:OX N = 7.0 ; C1 = 16%. Calc. for CI,H,,NO,C1 : C: = 56.2 ; H = 5.6 ; The chloride is a very stable substance, and is only decomposed slowly by boiling with potash. Some of it was treated for a week with t i n and strong hydrochloric acid warmed on a water bath. By blowing steam through the neutralised product of the reaction, an oil boiling at 246-5348' was obtained, which, unlike the original chloride, had basic properties and formed a platinum salt melting a t 208-210".When this oil is boiled with aqueous soda and an acid added to the solution, a pyridine acid melting a t 158-160" is precipitated. The platinum salt contained 25.4 per cent. of Pt, and the ether and acid were both free from chlorine. The substance which had been produced was, therefore, an ethplic ay-dimethyl pyridine /3-carboxylate, and is probably identical with a compound produced by Michoel (Re?*., 1586, 18, 2020) from ethylic aceqo- acetate. He found that the ether, C5H,N(CKJ3* COOC,H,, boiled a t 246-24'i0, the platinochloride melted a t l o l o , and the acid had a melting point of 166". This reduction of the chloro-derivative by tin and hydrochloric acid is of interest, because many of the chloropyridines are not acted on by nascent hydrogen produced in this manner, The compound A needs prolonged treatment with boiling and moderately concentrated soda t o effect its decomposition.The sodium salt produced is decomposed on the addition of hydrochloric acid, and the free acid is a t once precipitated. It is very insoluble in most solvents, but can be recrystallised from boiling water. When pure, it melts at a little above 300", about 304', and decomposes a t once at that temperature, carbon dioxide and pseudolutidostyril being produced. It crystallises with 1 mol. H,O, and has the formula C,H,NO,,H,O. Auchutz, Bendix, and Kerp (Ann., 1890,259, p. 174) obtained an acid melting at 275" by heating isodehydracetic acid with ammonia ; although they give the melting point as 2 7 5 O , it probably is the same acid, for, on heating, it yields carbon dioxide and pseudolutidostyril. The silver salt is thrown down as a white precipitate from neutral solutions.The coppel' salt is a light green precipitate. The Zecccl salt crystallises from concentrated solutions in small tufts composed of microscopical needles. The bawhra salt is also soluble, but crystallises from concen- trat ed solution e. Several analyses of the acids mere made which gave results agreeing with the formula C,H9N0,,K,0. As already st,ated, when it is heated it decomposes at its melting point, giving carbon dioxide and pseudolutidostyril N = 6.5; C1 = 16.6. Several salts of this acid were prepared and annlysed.ETHYLIC P-ARZIDOCROTONATE. 307 This reaction appears to be nearly quantitative. Five grams of the dried acid yielded 660 C.C.of carbon dioxide, and 3.6 grams of residue, the amount required by theory being 670 C.C. and 3.7 grams. The residue agreed in every respect with pseudolutidostyril ; it melted a t 180--181", and boiled at 306-301". The analyses t h a t were made also agreed with the formula C,K,NO. This substance was first prepared by Hantzsch (Bey., 1884, 17, 1026) by the action of sulphuric acid on CH, OH ( p n \(g \(+ CH, yo CH,*COOH, /?.< /"\ CH,<* $! I=;.CH, CH3. COOH. C C-COOH = HC CH + co, I I CH.3 A l e thylpseudolutidostyril. The methylpseudolutidostyril was then converted into pseudolutido- styril by heating with hydriodic acid. As very considerable mole- cnlar change must have occurred during the production of methylpseudo- lutidostyril, it is of interest to be able t o confirm the formula which Hantzsch suggested for pseudolutidostyril from the formation of that substance by a totally different set of reactions, CH./NH\ Yo CH Pseucloluticlosty Ti2 3 E HC According to Hantzsch, pseudolutidostyril, when heated with zinc dust, gave ny-dimethylpyridine. Before I had seen Hantzsch's paper, I had tried the experiment, and as the results were slightly different, and the amounts used very much larger, they are worth recording. I n one experiment, where 25 grams of the substance was heated with zinc dust, 12 grams of pyridine bases were obtained boiling between 150 and 170"; these, on fractional distillation, gave, at 150-160", 2 grams; 160--165", 6 grams ; 165-170", 4 grams. The portion boiling from 150-160" was converted into platminochloride and re- crystallised; it contained 31.0 per cent.Pt, and mas without doubt the substance [C,H,N(CH,),],,H,PtC1,, which contains 3 1 *2 per cent. Pt and has no water of crystallisation. ay-Dimethplpyridine boils at, 166-157".308 COLLIE : PRODUCTION OF PYRIDINE DERIVATIVES FRON The larger portion of the pyridine bases, however, boiled between 160" and 170°, and gave a platinochloride less soluble in water than the former one. After many crystallisations, the salt, which melted at 217", was repeatedly analysed. (1) C = 29.4 ; H = 3.9. (2) C = 29.5 ; H = 4.0. (3) C1= 33.1. (4) Six determinations of platinum, varying from 29.7 t o 29.9. The substance is, therefore, a trimethylpyridine or a collidine.CCSH~N(CH&,, H,PtCI, * [C,H,N( CH3)&H,PtClp Found. Lntidine. Collidine. C 26.9 29-4 29.4 H 3.2 3.7 3.9 C1 34.1 32.7 33a1 Pt 31.2 29.9 29.9 Some of the platinochloride was decomposed with hydrogen sulphide, and the free base obtained from the filtrate; its boiling point was 167-168". It gave C=79*2; H=9.1 ; N (by diff.)=11*7. C. H. N. Lutidine, C7H,N.. ................ 78.5 8.4 13.1 Clollidine, C,H,,N ............... 79.3 9-1 11.6 Found .............................. 79.2 9.1 11.7 From the boiling point, probably, this collidine is the symmetrical trime t hy lpyridine. According to Hantzsch (Ann., 1882, 215, 13), this collidine boils at 171-172", whilst Durkopf (Ber., 1888, 21, 2713) gives the boiling point 167-168". The remainder of the base was submitted to oxidation by perman- ganate of potash-for, according to Durkopf, uvitonic acid is pro- duced (pyridine-a-methyl-a'y-dicarboxylic acid), but the products were formed in such small quantity that no definite results were obtained.That it is a trimethylpyridine is of considerable interest ; and it is a curious fact that a substance like pseudolutidostyril should be thus changed into a collidine derivative when heated with zinc dust, and that Hantzsch's collidine compound with strong sulphuric acid should yield pseudolutidostyril. Moreover, the chlorolutidine obtained by the action of pentachloride of phosphorus on pseudolutidostyril seemsETHYL~C P-AMIDOCROTONATE. 309 to give nothing but lutidine (b. p. 156-158") when heated with zinc dust. This chlorolutidine is produced almost quantitatively, 25 grains of pseudolutidostyril yielding about 22 grams of the chloro-compound, a-Cl~loi*o-a'y-c~irnetl~l2~?/~idi7ze, C5NH2(C€33)2Cl.When pure, it boils at 212-214". An analysis gave C=59*0, H = 5.7, whiIst C7H,NC1 requires c' = 59.3, It combines feebly with hydrochloric acid, and forms a stable platinochloride, which, when analysed, gave 28.1 per cent. Pt. Theory for (C7H8NCl),,H,PtCl, = 28.1 per cent. The only may to prepare the hydrochloride is to saturate the oil with hydrogen chloride. The white solid hydrochloride thus formed was weighed, and it was found that the chlorolutidine had taken up 12.2 per cent. of hydrogenchloride, which is almost the amount necessary if 2 molecules of the chloro- lntidine react with 1 molecule of hydrogen chloride-1 2.8 per cent.H = 5.6. 2C7H,NCl + HC1= ( C7H,NCl),,HC1. The platinochloride seems, however, t o be the normal compound, for it gave 28.0 per cent. Pt, and (C7H,NC1),,H2PtCl, contains 28.1 per cent. Pt. /NH\ \ C / CH, Yo COUZ~OU?.L~ B, m. p . 166-167", COOC2H5* CH,* HC CH I The analysis and methods for the preparation of this substance have already been given (p. 304). When it is boiled with strong hydrochloric acid, it slowly decom- poses into the free acid (m. p. 190-191"), carbon dioxide, ethylic chloride, and pseudolutidostyril. It does not give an acetyl derivative when heated with acetic chloride or acetic anhydride, but, as already stated, it is hydrolgsed at once by alkalis (diffarence from compound A), and on adding an acid to the alkaline solution, the free acid crys- tallises out.Unlike the compound A, it does not react in a simple manner with pentachloride of phosphorus. Even when it is dissolved in various solvents, and the pentachloride of phosphorus is added carefully, con- siderable decomposition occurs, blackening, evolution of carbon dioxide and other gases being amongst the most noticeable results, whilst no pure substance could be obtained from the product of the action. With bromine, however, it forms a definite compound. When the compound310 COLLIE : PRODUCTION OF PTRIDINE DERIVATIVES, ETC. B is dissolved in glacial acetic acid, and bromine is added carefully, two molecular proportions of bromine have to be added before it re- mains in excess. The mean of three bromine determinations gave 44.7 per cent.Br., and on combustion C = 34.5 per cent., H = 3.3 per cent. The pure bromine compound melts a t 168-170". C10HllN03Br2 requires C = 34.0 ; H = 3.1 ; Br = 45.3 per cent. The bromide is hydrolysed a t once on treatment with soda; the free acid crystallises in small needles, and when heated to 256-258", melts and chars, giving off carbon dioxide, bromacetone, and hydrogen brom- ide. Although the compound A gives no hydrazone with phenyl- hydrazine, the compound B, when heated in a sealed tube with that re- agent, enters a t once into combination with it. It was found, however, that, even after many crystallieations, the substance was not pure. Results of analysis : C = 65.0 ; H = 6.3 ; N = 15.0 per cent. Calculated C,GH,,N,O, : C = 67.4 ; H = 6.6 ; N = 14.7.This compound, when heated, melted a t 227-228", blackening con- siderably, and gave a strong smell of aniline compounds, so that, although it had not been obtained in a pure condition, still there was no doubt that a hydrazone had been produced. When the compound B is treated even with dilute alkalis, i t dissolves, and on warming a t once hydrolyses. The free acid, which is obtained by adding hydrochloric acid to the solution of the sodium salt, crys- tallises from water, either in needles or flat, needle-shaped plates, con- taining no water of crystallisation. It melts a t 190-191", and on analysis gave results agreeing with the formula C,H,NO,. The sodium salt crystallises in large plates ; the bnrium salt seems t o be less soluble in boiling than in cold water ; the lead salt separates in leaflets from strong solutions; the silvw salt is thrown down as a flocculent precipitate in neutral solutions, and is moderately soluble in hot water, from which it can he crystallised. It contains no water of crystallisation, and gave on analysis 56.0 per cent. Ag. Theory for C,H,NO,Ag, : Ag = 56-0 per cent. Probably the hydrogen atom that is attached to the nitrogen atom, has beenreplaced by the silver as well as the hydrogen in the carboxyl group. The same result was obtained on analysing the silver salt of the isomeric acid (m. p. 300-304") from the compound A. 54.1 and 55.0 per cent. Ag. On heating this acid (m. p. 190-191"), it is noticed that copious effervescence of carbon dioxide occiirs the moment it melts; 10 grams lost 2.5 grams. According to the equation, C,H9N0,, = C,H,NO + CO,, it should lose 26 per cent. The residue in the flask is almost pure pseudolutidostyril, identical in ,,YOUNG : OXIDATION OF PHENYLSTYRENYLOXYTRIAZOZE. 311 every respect with that obtained by heating the acid (m. p. 300-304"). The simplest method of explanation is that the acid has the following formula : /NH, / \ HC CH ff.200 H*CH2*E Yo That it is a substituted acetic acid also receives additional support from its behaviour with ferric chloride. I n neutral solutions, it gives at first a reddish coloration, bnt on boiling, the yellow ferric salt is at once precipitated,

ISSN:0368-1645    

DOI:10.1039/CT8977100299

出版商:RSC    

年代:1897

数据来源: RSC

摘要:

YOUNG : OXIDATION OF PHENYLSTYRENYLOXYTRIAZOZE. 311 XXVII.-Otxitlatio~z of Phciz~~lstyi.c..r~ylox~~jiinzo7e. By GEORGE YOUNG, Ph.D., Firth College, Sheffield. THE formation and properties of phenylstyrenyloxytriazole, have been described by Widman (Be?.., 1896, 29, 1952) and by me (this vol., p. 200). Widman oxidised this oxytriazole by means of potassium permanganate in an alkaline solution and obtained phenyl- oxytriazole in place of the expected phenyloxytriazolecnrboxylic acicl, and therefore represented the action by the eqnation C,H,* 'OH5>C,N:,* C2R, OH + 0, = C6H,,* C,X,H* OH + C,H,* COOH + CO,. The experimental details contained in this paper, however, show that the above equation represents merely the final result, the first stage being the formation of the potassium salt of phenyloxytri~~oleca.1.- boxylic acid.+ C,H,* COOK + 2H,O. The metallic and ethereal salts of the new acid seem quite stable, but the free acid, immediately it is liberated, decomposes into carbon dioxide and phenyloxytriazole, Etherification of the hydroxyl does not seem t.0 increase the stability of the carboxylic group. These results are of interest when compared with the account given C,H,* C,N,(OK)*COOK + 2HC1= 2KC1+ CO, + C,H,*C,N,H*OH.31 2 YOUNG : OXIDATION O F PHENYLSTYRENYLOXYTRIAZOLE. by Bladin (Ber., 1890, 23, 1810, 3785), of the behaviour of phenyl- triazoledicarboxylic acid. This acid is only stable in combination ; on liberation of the free acid, it loses 1 molecule of carbon dioxide and phenyltriazolemonocarboxylic acid is formed ; Bladin's observations C,H,*N*N show that this acid has the constitution ,b.,>C*COOH,* the carboxylic group in position 5 having undergone decomposition. Method of Oxidation.Phenylstyrenyloxytriazole was dissolved in an excess of caustic potash, cooled, and a solution of potassium permanganate added slowly with shaking until no further change of colour could be observed ; after standing overnight, the excess of potassium permanganate was destroyed by alcohol. The filtered solution was treated with an excess of ammonium chloride, warmed, and a solution of calcium chloride added in excess ; the precipitate, on examination, proved to be calcium carbonate. The filtrate was concentrated over the water bath, cooled in a freezing mixture, and dilute hydrochloric acid added ; this threw down a white precipitate, from which, after a few moments, a slow and steady evolution of carbon dioxide took place.After removal of benzoic acid by a current of steam, there remained a small amount of a white, crystalline substance which melted at 272-273". Widman gives the melting point of phenyloxytriazole as 273-274" (Beel.., 1896,29, 1953). Various attempts to isolat,e phenyloxytriazolecarboxylic acid or one of its inorganic salts were unsuccessful. A fresh quantity of phenylstyrenyloxytriazole was oxidised by alka- line potassium permanganate, and after removal of the excess of oxidis- ing agent, the filtered solution was treated with an excess of ammonium sulphate and gently warmed until almost neutral. The addition of silver nitrate to this then threw down a brownish precipitate, which was dried on a porous plate, and finally in an air bath a t 50 - 60".The mixture of dry silver salts thus obtained was treated with ethylic iodide, and the product extracted first with warm ether and then with boiling alcohol. The ethereal solution, on evaporation, left an oily residue, which smelt of ethylic benzoate when heated on the water bath, and,on being extracted with warm, light petroleum (b. p. 40--5O"), yielded small, white needles melting a t 80-81". The alcoholic solution also yielded small, white needles which melted at 81-82'. Both crops of crystals, when recrystallised from dilute alcohol, gave See Andreocci (Ber., 1892, 26, 225), and Baniberger and de Gruyter (Ber., 1893, 26, 2385), * Bladin exchanges positions 3 and 5.YOUNG : OXIDATION OF PHENYLSTYRENYLOXYTRIAZOLE.313 long, white needles which melted constantly at 82-83", The yield was 33 per cent. of the theoretical, On analysis, figures were obtained agreeing with those required by the formula C,H, C,N,( OC,H,) COOC, H,. 0.1079 gave 09.355 CO, and 0.0554 H,O. C = 59.52 ; H = 5.70. 0.2101 ,, 29.3 C.C. moist nitrogen a t 14" and 751.3 mm. N = 16-21. Ethylic phenylethoxytriazolecarboxylate is fairly soluble in warm ether and light petroleum, and easily in alcohol or benzene. It is easily hydrolysed by alcoholic potash. The amide, CGH,*C,N 3(OC,H5)* CONH,.-When the ethylic salt was dissolved in absolute alcoholic ammonia, and the solution evapo- rated, clusters of white, well-defined needles were deposited, easily soluble in alcohol or ether, but only slightly so in warm, light petroleum.On the addition of light petroleum to the ethereal solution, small, white needles were deposited which melted a t 149-150". C,,H,,N,O, requires C = 59.77 ; H = 5-71 ; N = 16.09 per cent. 0.1397 gave 0.2904 CO, and 0.0663 H,O. The amide is easily hydrolysed by boiling alcoholic potash. C = 56.69 ; H -- 5.27. CllHl2N4O, requires C = 56.89 ; H = 5-17 per cent. ammonia evolved mas collected in standard acid and titrated. The 0.5264 gave 0.0364 NH,. NH2 = 6.50. C11Hl,N,02* NH, requires NH, = 6.89 per cent. The alkaline alcoholic solutions of potassium phenylethoxytriazole- carboxylate, CGH,* C,N,*(OC,H,)*COOK, obtained by the hydrolysis of the ethylic salt and of the amide, were mixed together, the alcohol evaporated, and the solution neutralised by the addition of ammonium sulphate, and boiling.On adding silver nitrate, the silver salt sepa- rated as a white, flocculent precipitate, which, after drying on a porous plate and in a vacuum over sulphuric acid, lost weight a t 60" very nearly equivalent to 2H,O. 0.5492 lost 0,0518. H,O = 9.43. 0.4974, dried a t 60°, gave 0*2071 AgU. Ag = 31.34. C,,H,,N,O,Ag + 2H,O requires 2H,O = 9-57 per cent., and C1,H,,N,03Ag requires Ag = 31-76 per cent. Silver phenylethoxytriazolecarboxylate was dissolved in warm am- monia, a slight excess of sodium chloride added, the solution boiled until almost neutral, and then filtered ; the alkali salts of the carbo-314 DYMOND AND HUGHES : FORMATION OF DITHIONIC ACID xylic acid seem to be quite stable in boiling water.The solution of the sodium salt, prepared in this way, was concentrated and cooled in a freezing mixture ; on adding hydrochloric acid, a slight evolution of gas took place, and at the same time an oily substance separated, which, after extraction with ether and recrystallisation from dilute alcohol, formed long, flat, white needles melting at 60". On analysis, figures were obtained agreeing with those required by the formula C,H,* C,N,H*OC,H,. 0.1550 gave 0.3603 CO, and 0.0825 H,O. 0.2011 ,, 38.8 C.C. moist nitrogen a t 15" and 752.5 mm. N = 22.37. C= 63.39 ; H=5-91. C,oHllN3O requires C = 63.49 ; H = 5.82 ; N = 22.22 per cent. Phenylethoxytriazole is easily soluble in ether, alcohol, and benzene, but only slightly in light petroleum. It is not attacked by boiling alkalis or acids. I n order to confirm the constitution assigned to the phenylethoxy- triazole obtained in the manner described, it was compared with a specimen prepared by the action of ethylic iodide tm the silver derivative of 1-phenyl-3-oxytriazole. Widman describes (Be?*., 1893, 26, 2613) the preparation of phenyl- oxytriazole by the action of formic acid on phenylsemicarbazide, and I have found this action to give very good yields, amounting to 75 per cent. of the weight of phenylsemicarbazide taken. The substance melted at 274-275". The ethyl derivative, C,H,* C,N,H* OC,H,, formed long, flat, white needles which melted a t 60°, and possessed solubilities identical with those of the phenylethoxytriazole prepared from phenylstyrenyloxytriazole. 0.1491 gave 0,3464 CO, and 0.0805 H,O. C = 63.35 ; H = 5*99. C,,H,,N,O requires C = 63.49 ; H = 5.82 per cent.

ISSN:0368-1645    

DOI:10.1039/CT8977100311

出版商:RSC    

年代:1897

数据来源: RSC

摘要:

314 DYMOND AND HUGHES : FORMATION OF DITHIONIC ACID XXVIlI.-&br./matio/lL of Dithionic Acid by the Oxidation of SZdphu~oas Acid wit?$ Potassium Perwaawpnate. By THOMAS 5. DYMOND and FRANK HUGHES. IT is usually stated that sulphurous acid is oxidised by potassium perrnanganate to sulphuric acid. Sulphuric acid is undoubtedly the principal product of the action, but if an acidified solution of sulphurous acid of known strength is titrated with a standardised solution of potas sium permanganate, the permanganate ceases to be decolorised when the quantity used is aboiit nine-tenths of that necessary to completely oxidise the sulphurous acid to sulphuric acid. Lunge and SmithBY THE OXIDATION OF SULPHUROUS ACID, ETC. 315 (J. Soc. Chem. Ind., 1883, p. 460) ascribe this discrepancy to loss of sulphur dioxide by volatilisation.As the constancy of the results under different conditions of dilution gave us reason to believe that this was not the true explanation, we determined to carry out the ex- periment under conditions in which loss by volatilisation and also atmos- pheric oxidation were impossible. The apparatus employed mas that suggested by one of us, in con- junction with Professor Dunstan, for the estimation of nitrites (Phtcinb. J., 1889, [III.], 19, 741). A round-bottomed flask is fitted with an india-rubber cork and wide glass tube, and to this is connected a burette, by a piece of pressure tubing, which can be closed bya screw clip. Water is boiled in the flask until the apparatus is free from air, and then the clip is screwed up and the flask cooled.A liquid can now be drawn into the partially vacuous flask from the burette, and titra- tions are carried out by filling the burette with the standardised solu- tion. Before using the apparatus for tthe purpose of these experiments, it mas ascertained that the india-rubber connections had no appreciable action on the solutions used. The sodium sulphite employed in the experiments mas crystallised from the commercial salt until free from sulphate and carbonate. When estimated by means of iodine, the purified salt gave results corres- ponding exactly with the formula Na,SO,, + 7H,O. 0.4 grams of the pure salt, dissolved in recently boiled water, mas run into the flask from the burette, and dilute sulphuric acid, also recently boiled, was added. The burette was mashed out with the standardised solution of permanganate and then filled with it.The permanganate solution mas now run in little by little, the flask meantime being constantly shaken, to prevent the permanganate from remaining unattacked in the glass tube. The permanganate required in a series of eight con- cordant determinations was 1s-'74 C.C. (1 C.C. = 0*001206 gram available oxygen), equal to 0,0226 grain of oxygen absorbed. The oxygen required to oxidise 0.4 gram of Nn,SO, + 7H,O to sulphate is 0,0254 gram. These experiments, made under conditions in which volatilisation or atmospheric oxidation of sulphurous acid was impossible, show that only 89 per cent. of the oxygen necessary to oxidise the sulphurous to sulphuric acid was absorbed, and this can only be explained by supposing that a part of the sulphurous acid was oxidised to an inter- mediate compound incapable of further oxidation by the permanganate solution.It occurred to us as most probable that the compound was dithionic acid, first prepared by TvVelter and Gay Lussac in 1819, by passing sulphur dioxide into water containing manganese dioxide in suspension. That this was the substance was rendered more probable by the observation of Berthier in 1843 ( A ~ N . Chinz. Phys., [iii.], 7,316 DYMOND AND HUGHES : FORMATION OF DITHIONIC ACfb p. 77),* that when sulphur dioxide is passed into solutions of potassium chromate or dichromnte, dithionic acid is formed in addition to sulphuric acid. Inorder to test this supposition, the experiment was repeated on a large scale.The gas spontaneously volatilising from liquid sulphur dioxide was passed into cold water, and potassium permanganate solu- tion was run in at the same time, care being taken to keep the sulphur- ous acid in excess until the end of the operation, when the exact addi- tional quantity of permanganate required was added. The sulphuric acid and manganese were precipitated by baryta, and the excess of baryta precipitated by subsequently passing carbon dioxide through the mix- ture ; the filtered liquid, when evaporated on the water bath, yielded crystals which had the properties of potassium dithionate. When heated alone or with hydrochloric acid, sulphur dioxide was evolved and sul- phate of potassium left, but no sulphur set free; moreover, when heated with nitric acid, sulphate of potassium was the only product, all these reactions being characteristic of a dithionate.Before obtaining the crystals pure enough for analysis, a tedious process of recrystallisation was necessary in order to get rid of the potassium carbonate left in the residue when this process of isolation is employed. This, however, provided an opportunity of searching for products of the oxidation of sulphurous acid other than dithionic and sulphuric acids, but no fractions were obtained which gave evidence of the existence of a third substance, and it was concluded that dithionic and sulphuric acids were the only products. The potassium dithionate finally obtained had a neutral reaction, was free from carbonate and sulphate, and gave the same figures on analysis when recrgstallised.For identification, several methods of analysis were employed. (A.) The aqueous solution of the salt was heated with hydrochloric acid in the air-free flask (closed), until decomposed into sulphurous and sulphuric acid, and the sulphurous acid estimated by solution of iodine run in from the burette. (B.) The aqueous solution of the salt was boiled with hydrochloric acid in the air-free flask (open), until free from sulphurous acid, and the remaining sulphuric acid esti- mated as barium sulphate. (C.) The solution of the salt was boiled with hydrochloric acid, the sulphuric acid produced precipitated with baryta water, the excess of baryta removed by carbon dioxide, and the potassium estimated in the solution as platinochloride.The results of the analyses were as follows. * We are indebted to Jklr. W. J. Sell for this reference. The fact is nientioiied in both Gmelin’s Handbook and Watt’s Dictionary (original edition), but the reference given in both is wrong.BY THE OXIDATION OF SVLPHUROUS ACID, ETC. 317 Found. Calculated for K,S,O, A. Sulphur, liberated by hydro- B. Sulphur, liberated by hydro- lysis as SO, . . . . . . . . . . . . . . . . . . . . . 13.60 ,, 13.44 ,, C. Potassium ..................... 32.53 ,, 32-77 ?, lysis as SO, ..................... 13.47 per cent. 13.44 per cent. These results fully identify the substance as potassium dithionate not only loy the percentage of potassium and total sulphur, but also by the characteristic hydrolysis of dithionic acid into equivalent pro- portions of sulphurous and sulphuric acids.Having demonstrated that dithionic acid, as well as sulphuric acid, is a product of the oxidation of sulphurous acid by permanganate of potassium, we next endeavoured to obtain a further knowledge of the reaction by determining the influence of dilution, temperature, and acidity on the relative proportions of the products. For these experi- ments, the apparatus previously described and a solution of permanga- nate of the same strength were employed. T.--lnj.uence of Dilution (Tenaperutwe and Acidity Constant). Na,SO, + 7H,O taken Water. Permanganate required. 1. 0.4 gram. 21 C.C. 18-9 C.C. 2. 0.4 ,, 61 9 9 18.7 ,, 3. 0.4 I , 161 ,, 18.7 ,, IL-InJuence of Teruperntzwe (Dilvtion and Acidity Constant).1. 0.4 gram. 80" 18.8 C.C. 2. 0.4 ,, - 2" 18.8 ,, Na,SO, + 7H,O. Temperature. Permanganabrequired. III .--lnJEuence of Acidity (Dilution cmd Ternperatwe Constunt). Na,SO, + 7H,O. Dilute H,SO,, 5% Permanganate required. 1. 0.4 gram. 5 C.C. 1s.s C.C. 2. 0.4 ,! 60 7 7 18.6 ,, 3. 0.4 ,, 150 9 9 18-6 ,, These experiments show that a variation in the amount of water or of acid, or in the temperature, does not produce any appreciable variation in the proportion of sulphurous and sulphuric acids. This remarkable result indicates that the dithionic acid is not a chance product, but that its for- mation is an essential part of the reaction, Dithionic acid is interme- diate between sulphurous and sulphuric acids, its hypothetical anhy- dride being S,O,, and it might be supposed t o be formed as a first stage in the oxidation of sulphurous to sulphuric acid.That this is not the case is, we think, made clear by the foregoing experiments, for varia- VOI,. LXXI. Z318 MATTHEWS : APPARATUS FOR “ STEAM DISTILLATION.” tion in the conditions of temperature and dilution would certainly affect the quantity of dithionic acid left unoxidised. It seems much more probable that the formation of dithionic as well as of sulphuric acid is due to the different oxidising effects of the oxides of manganese during the various stages of reduction. It is to be sup- posed that, in reducing the Mn,07 of the permangate to MnO,, the sulphurous acid is oxidised to sulphuric acid completely, for when a solu- tion of sulphurous acid is poured into excess of permanganate solution, sulphuric acid is the only product.If manganese dioxide, even in a very fine state of division and diffused in water, is added to excess of sulphurous acid solution, both dithionic and sulphuric acids are pro- duced, but the proportion of the former appears to be larger than when potassium permanganate is used. It appears, therefore, that the formation of dithionic acid is due to a stage in the reduction of MnO, to MnO. The relative proportion of the two acids produced almost exactly corresponds with the equation 1 7H,SO, + 6KMn04 = 2K,S,O, + K,S04 + 6MnS0, + 6H,SO, + 11 H,O. According t o this equation, 88.2 per cent. of the oxygen required to oxidise sulphurous to sulphuric acid is used ; in oiir experiments, 88.9 per cent. of that required was used. As the proportion of dithionate represented by the above equation is that which would be produced were it formed during a stage of the reduction of the permanganate corresponding with the conversion of Mn,O, into 3Mn0, it might be expected that the oxide Mn,O, would itself oxidise sulphurous to di- thionic acid. If, however, this oxide, prepared by heating the dioxide to fusion, be finely powdered and diffused in water, and the mixture added to the solution of sulphurous acid, sulphuric acid is the only product of oxidation. This fact, however, does not preclude the pos- sibility of there being a corresponding stage in the reduction of the dissolved manganese compounds in which dithionic acid is produced, At any rate, its formation must be due to the weak oxidising action of the permanganate in one of the later stages of its reduction. COUNTY TECHNICAL LABORATORIES, CHELJISFORD.

ISSN:0368-1645    

DOI:10.1039/CT8977100314

出版商:RSC    

年代:1897

数据来源: RSC

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318 MATTHEWS : APPARATUS FOR “ STEAM DISTILLATION.” XXIX -Apparatus for ‘‘ Steam Distillution. ” By FRANCIS EDWARD MATTHEWX. FOR some time past., the author has taken advantage of the fact that during the process of steam distillation various solid substances of fairly high melting point are deposited in, and adhere to, the interior of the condenser, so that by substituting a reflux condenser for one in theMATTHEWS : APPARATUS FOR ‘‘ STEAM DISTILLATION.” 319 ordinary position, the.process becomes a continuous one, it being merely necessary from time t o time t o remove the substance deposited in the condenser. By using condensers of sufficient interior diameter, the removal of this deposit need not be often repeated, and consequently the separation or purification of the substance can be left almost to itself until complete.The advantages of an automatic method of steam distillation were so obvious, that attempts mere made to construct an apparatus which could, inlike manner, be used for the separation of liquid substances. I n the case of liqnids heavier than water, trial was first made of a reflux condenser having near its lower extremity a T-piece connected with a flask, so that the condensed mixture of water and theliquid should FIG. 1. flow down the T-piece into the flask, when the heavy liquid would sink to the bottom and the water flow back from the surface into the boiling-flrsk. It was found that this arrangement did not work a t all, from the fact that the liquid was in the form of small drops, which remained floating on the surface of the water, and consequently returned to the boiling-flask along with it.It was obvious that, in order to succeed, a quantity of the heavy liquid sufficient to produce a large drop must be collected, and then the drop, when it becomes of a certain size, will necessarily sink. This object was attained in the following may, The vessel in which the mixture was boiled was an ordinary flask, in size sufficient to readily contain the liquid to be steam distilled along with two or three times its volume of distilled water, this boiling-flask (Fig. 1) being connected 2f: 20 MATTHEW4 : APPARATUS FOR ‘( STEATVI DISTILLATION.’’ by a cork to a receiver, which consisted of an ordinary distillation-flask having a wide side-tube. This side-tube was bent downwards, 3 or 4 inches from the end, a t an angle of about 120”, so that when the receiver was upright, the upper part of the side-tube was inclined downwards, t’he lower part being nearly vertical.About 1 inch from t,he end of the side-tnbe a hole was made large enough to carry off thc steam from the boiling-flask. It mas found that this hole allowed the diameter of the side-tube to be considerably reduced, for in a tube in which vapour is passing in one direction and water in the other, the chief point at which a block is usually produced is a t the lower end of the tube where the water begins to form drops; by alloming the vapour to enter the tube a t the side, higher up, this tendency to choking a t the end is obviated to a very great extent, and consequently a much narrower tube can be used.The reflux condenser connected with the receiver was of the following construction. Its inner tube was sufficiently narrow to pass readily into the neck of the receiver, and the portion below the water-jacket had to be of sufficient length (about 9 inches) to admit of a bend being made in it a t an angle of about 120°, the portion below the bend penetrating the receiver to R depth of about 2 inches below its side- tube. In this part of the tube, about 3 inches from its end on the side away from the bend and just below the cork, a hole was made to admit the mixed vapours to the condenser. The apparatus works as follows. The liquid to be distilled is placed in the boiling-flask together with two or three times its volume of water, the flask is connected to the side-tube of the receiver, which is filled with distilled water up to the junction of the side-tube, and the condenser is inserted into the receiver to a depth of about 2 inches below the water-level.On raising the contents of the first flask to the boiling point, a stream of the mixed vapours passes through the side- tube and into the upper part of the neck of the receiver, whence it is forced through the hole into the condenser; here it is condensed, and the liquid runs down the side of the condenser away from the hole until a drop of the heavy liquid sufficiently large to sink is formed in the lower end of the condenser; as the liquid condenses, it displaces an equal volume of water from the receiver, which flows domn the side- tube back into the boiling-flask. As the receiver, if protected from direct radiation, remains fairly cool during the whole operation, the volume of liquid in the boiling-flask remains almost constant until the distillation is finished.For automatically skeam-distilling liquids lighter than water, it is obvious that the water must be transferred from the bottom of the receiver back again to the boiling-flask. This object was attained satisfactorily by one or other of the following arrangements, which, although identical in principle, differ in various details.MATTHEWS : BPPARATUS FOR STEAM DISTILLATION.” 321 1. The boiling-flask (Fig. 2) is ail ordinary distilling-flask of suitable size, having the side-tube bent vertically downwards 2 or 3 inches from the end when the flask is upright. The receiver is a Woulfe’s bottle, with either twd or three necks.Into the neck nearest to the boiling-flask, a straight, upright tube is fixed by means of a well-fitting cork, of such a length that, one end being at the bottom of the Woulfe’s Bottle, its other just touches the lower end of the bent side-tube of the boil- ing-flask, to which i t is connected by an india-rubber joint. The second neck of the Woulfe’s bottle is fitted with a vertical T-tube, which fulfils the following conditions. It must dip 2 or 3 inches into the Woulfe’s bottle, and the T-joint must be suf- ficiently high up to allow of the for- mation of a column of (light) liquid sufficient to overcome the pressure of a column of water the height of which is the difference in level be- tween the surface of the water in the receiver and the point where the side- tube meets the neck of the boiling- flask.Into the upright T-tube a condenser, of any suitable form, is fixed (a narrow vertical condenser with a hole made in it, as previously described, has been found to work well). The boiling-flask is connected with the side-tube of the vertical T-tube by means of a tube bent a t right angles, n cork, and ail india- rubber connector. It is essential that all the corks in the Woulfe’s bottle should fit tightly. To me the apparatus, distilled water is poured into the receiver till the bottom of the T-tube is just F I G . 2. - :” covered; the mixture to be distilled is placed in the boiling-filtsk and heated ; the mixed vapours pass into the T-tube, and thence into the condenser; the condensed liquid soon forms a coltimn in the upright T-tube, which gradually forces the water up the other upright tube back into the boiling-flask.322 MATTHEWS : APPARATUS FOR “STEAM DISTILLATION.” The receiver should be screened from direct radiation as much as possible, although the expulsion of a small amount of air from the upper part of the Wonlfe’s bottle is unimportant. The chief objection to this form of apparatus is the india-rubber connection between the boiling-flask and the T-tube, as this is liable to attack by the vapoure of some liquids, whilst if no joint is made, the strain produced in fitting the apparatus together is dangerous.The second india-rubber FIG. 3 . 1 I A FIG.4. r- C joint does not matter, as only cool water passes through it. Apart from this, the apparatus works perfectly ; and it has the advantage that it can be constructed in a very short time from apparatus found in any ordinary laboratory. 11. In the apparatus Fig. 3, the Woulfe’s bottle is replaced by a separating-funnel with two necks; this has the advantage that the dia- tillate can be drawn off by the tap at the bottom without dismantlingRUHEMANN : &KETONIC ACIDS. 323 the apparatus, whilst the boiling-flask is an ordinary flask, instead of the distilling-flask used in I. The connection between the boiling-flask and the receiver and condenser is made by means of a piece of appara- tus with two T-tubes, as is shown in Fig. 4. The boiling-flask is con- nected at A by means of a cork, B corresponds t o the side-tube of the distillingflask in the previous arrangement, and is connected, best by a double india-rubber joint, to the tube passing to the bottom of the re- ceiver; the condenser is connected a t C, and the end, D, passes 2 or 3 inches into the receiver.By this means, the exposure of india- rubber to hot vapour is avoided. The apparatus works just in the same manner as the previous one, and a detailed description is unnecessary. Liquids heavier than water may also be distilled in this form of apparatus, the tube through which the water returns being shortened, so as to allow of the water being drawn off near the surface. From the relatively small amount of liquid necessary for these pro- cesses, ‘‘ steam distillations ” can readily be carried on in the vapour of higher boiling liquids, and I am in hope that some new separations may be made by these means. I have found that, in many cases, the rapidity of the distillation can be greatly increased by dissolving some substance, such as sulphuric acid or calcium chloride, in the water of the boiling-flask. Many organic liquids bump very badly when boiled with water, and to obviate this, a couple, made by soldering a piece of zinc foil to a piece of platinum foil, may be used with advantage, wherever possible ; thus aniline, which bumps furiously when boiled with water, can be readily distilled without any bumping when the couple is added. I n conclusion, I wish to express my thanks t o Professor McLeod for the kindly interest he has taken in this work, and for some important suggestions he has made. ROYAL INDIAN ENGINEERING COLLEGE, COOPER’S HILL, STAINES.

ISSN:0368-1645    

DOI:10.1039/CT8977100318

出版商:RSC    

年代:1897

数据来源: RSC

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RUHEMANN : &KETONIC ACIDS. 323 XXX.-ContYibzctions to the Knowledge of the P-Ketoizic Acids. Part 111. By SIEGFRIED RUHEMANN, Ph.D., M.A. THE compounds formed by the action of ethylic chlorofumarate and ethylic cc-chlorocrotonate on ethereal saltsof P-ketonic acids have hitherto beenregardedas hgdrogenisedfurfuranderivatives (Trans., 1896,69,530, 1383), and this view seemed to agree well with their behaviour. Further study, however, has led to results which modify this view and tend to show that these substances must be regarded as ketonic compounds. It was stated(Zoc. cit.) that the ethereal salt formed from the sodium deriva-324 RUHEMANN : CONTRIBUTIONS TO THE tive of ethylic acetoacetate and ethylic chlorofumarate was to be repre- sented by the formula I, and that this expression agreed with the result C H, C=y COOC,H, CII; CO*FH* COOC,H, O--CH*COOC,H, CH* COOC,H, I.1 YE€*COOC,H, 11. COOC,H, of the refractometric behaviour of the compound. An error, however, was made in the calculation of the molecular refraction ; the number 71 m94, there given, corresponds with that required for ethylic acetoaconi- tate, JI, which agrees with the refractrometric constant found (Zoc. cit., p. 532) 72.23, whilst formula I requires the value 70.19. It was shown that, in using ethylic chloromaleate, the same compound was formed as in the interaction of the sodium derivative of ethylic: acetoacetate with ethylic chlorof umarate. This fact, which was brought forward as a further argument in favour of the view there expressed, must be explained by assuming a molecular transformation.On the other hand, formula I1 admits of as ready an explanation of its trans- formations as does formula I, and is, moreover, in full agreement with the behaviour of ethylic chlorofumarate and ethylic a-chlorocrotonate towards the sodium derivatives of other P-ketonic acids. Corresponding formule have to be attributed to the ethereal salts formed from ethylic benzoylacetate and ethylic chlorofumarate, and also t o that obtained by the action of ethylic acetoacetate on ethylic a-chlorocrotonate, namely, C,H,* CO*YH* COOC,H, C,H,* C(0H) : y.COOC,H, I_;'.COOC,H, or g *COOC,H, CH* COOC,H, CH* COOC,H, Ethylic benzoylaconitate. CH,* CO*YH*COOC,H, g*COOU,H, CH* CH, Ethylic aceto-8-butylenedicarboxylate. The formation of acetonylmalic acid * and of acetophenylmalic acid * Dr.A. Hutchinson has been kind enough to make the following crystallographic measurements of acetonylmalic acid. Crystalline system :-Monoclinic (Holohedral). a : b : ~=0'719 : 1 : 0.478. 8 = 53" 8'. Forms observed :-c(OOl), p{110), o{ill]. The following measurements mere made. Angle. Mean value. Calculated. pp' = 1 i o : i i o 120" 10' - pc = 110:001 58 40 oc = 111 :001 47 30 - dl,'" = iii :iii 60 50 51" 0'KNOWLEDGE OF THE @-KETONIC ACIDS. 32.5 from ethylic acetoaconitate and from ethylic benzoylaconitate respec- tively is brought about by the elimination of carbon dioxide, accom- panied by the addition of 1 moleculo of water, and their formul2e do not, therefore, differ from those given before; they are expressed by the symbol R*CO*CH,* C(OH)(COOH)*CH,* COOH or R*CO*CH,* CH(COOH)*CH(OH)-COOH (R denoting CH, or C,H,).The constitution of the compounds formed from ethylic acetoaconi- tate, and from ethylic benzoylaconitate, under the influence of ammonia, needs no modification, notwithstanding this change of view. But the product resulting from the action of ammonia on ethylic aceto-/3-buty- lenedicarboxylate (Zoc. cit., p. 1393) has t o be regarded as t~ monamide of the formula CH; CO*YH.CONH, CH,. UO*YH* COOU,H, g*C1OOC,Hj or E-CONH, C-CH, C-CH, Ethylic chlorofumarate, as shown before (Zoc. cit., p. 13S6), reacts with the sodium derivative of ethylic acetomethylacetate with elimina- tion of ethylic acetate and formation of a compound which, in the light of the former view, was regarded as ethylic f urfurandicarboxylate, CH,; C=$!*COOC,Hj 1 CH I I 1 O-C*COOC,H, This constitution, however, does not agree with the result of further study, which led to the conclusion that the reaction takes place as indi- cated by the following equation : COOC,H, + CC1<COOC,H5 CH3 CH*COOC,H, = CH,.CO.CNa< NaCl + CH,. COO Y(CH,)*COOC,H, = NaCl + CH;COOC,H, + COOC,H, CH*COOC,H, COOC,H, CH3' co*C%:CH*COOC,Hj The crystals were obtained from aqueous solution, and a large number from three different preparations examined. All the crystals are of well-marked rhombohedra1 habit. This is due to the equal development of the faces c and p , and t o the near equality of the angles 001 : 110 =58" 40' and 110 : llO=59" 50', which give to the crystals the appearance of obtuse rhombohedra. The form o is quite subordinate, and only found on a few individuals. None of the crystals lent theinselves to accurate determination, for whilst the faces of c and o are iairly bright and smooth, those of the prismp are invariably much rounded, even on the smallesr; crystals.The angles and axial ratios given above are therefore to be regarded as rough approximations only, since the angle cp was the only one which could be satisfactorily measured. No definite creavege was observed. The extinction on 1' makes an augle of 26" with the edgeppc.326 RUHEMANN : CONTRIBUTIONS TO THE The compound appears, therefore, to be ethylic acetoallylenedicstr- boxylate. This formula is supported by the action of aniline on the ethereal salt.Aniline dissolves it, and the solution, after being boiled for half an hour, and then acidified with hydrochloric acid, gives a dark red precipitate, which becomes yellow when washed with ether. It dis- solves in hot dilute spirit, and, on cooling, crystalliees in glittering, yellow plates, melting a t 180". The analytical numbers agree with the formula C17H,,N0,. 0.1882 gave 0,4650 CO, and 0*1082 H,O. C = 67.38 ; H = 6.42. 0.3124 ,, 1 2 C.C. moist nitrogen a t 26" and 755 mm. N = 4.23. 0.2980 ?, 11.5 ,, ,, ?, ,, 20' ,, 763 ,, . N=4*43. C17H,,N0, requires C = 67.77 ; H = 6.31 ; N = 4.65 per cent. The substance is readily soluble in alcohol, insoluble in water, and is decomposed by boiling hydrochloric acid with formation of aniline ; it therefore resembles anilpyroracemic acid in its properties.The forma- of such a compound from the ethereal salt, C,,H,,O,, excludes the formula brought forward before, and points to the view that it is to be regarded as ethylic acetoallylenedicarboxylate. The constitution of the substance formed from it under the influence of aniline is, therefore, The view with regard to the constitution of the acid, C,H,O,, result- ing from the hydrolysis of the ethereal salt of the formula C,,H1405, requires also to be modified. For this acid, there are various formuh possible ; the expression CH, -CO*CH:C:CH* COOH, which at first would seem probable, does not explain the behaviour of the compound described before (Zoc. cit., p. 1394). The properties of the acid are SO similar to those of coumalic acid, that one might assign to it an analogous constitution-such as CH,* CK0 C(oFd>CH, and regard it as methylhydroxycoumalin. This substance is readily etherified by saturating its solution in methylic alcohol with hydrogen chloride.The liquid is allowed to stand overnight, then poured into ice-cold water, extracted with ether, and the unchanged organic acid removed by dilute sodium carbonate. On evaporating the ether, an oil remains, which solidifies after some time. It crystallises from ether in colourless plates, melting at 139-1 40°, and is hydrolysed on boiling with water. Analysis of the compound, dried in a vacuum over sulphuric acid, gave numbers agreeing with the formula C,H,(CH,)O,. 0.2135 gzve 0.4694 CO, and 0.1065 H,O. C=59-96; H=5*54. 0*2070 ,, 0.4525 ,, ,, 0.1040 ,, .C = 59.62 ; H = 5.5s. C,H,O, requires C = 60.0 ; H = 5.71 per cent.KNOWLEDGE OF THE &KETONIC ACIDS. 327 Assuming that the constitution of the compound C,H,O, is to be expressed by the above formula, it mould follow that the etherification is not brought about by an opening. of the coumalin ring, unless, at the same time, a transformation takes place which leads to the forma- tion of methylic acetoallylenecarboxylate, CH,. CO*CH:C:CH* COOCH,. Experiments with the view of solving this question are in progress. Action of Ethglic a-Chloroci*otonccte o n Ethglic Benxoylacetccte. This is quite analogous to the behaviour of the former ethereal salt towards ethylic acetoacetate. The reaction is carried out in the usual manner, by mixing ethylic benzoylacetate with the calculated quantity of sodium dissolved in absolute alcohol, and gradually adding the equiva- lent amount of ethylic a-chlorocrotonate.The mixture is boiled on the water bath in a flask until it is no longer alkaline, using a reflux con- denser ; the alcohol is then evaporated, the residue poured into water, and the ethereal salt extracted with ether. The oil remaining after removal of the ether boils a t 195-200" under a pressure of 10 mm., and has the density d 15'/15'= 1.1361. It is of a pale yellow colour? and its alcoholic solution turns faintly red on the addition of ferric chloride. On analysis, the following numbers were obtained. 0-2000 gave 0.4960 CO, and 0.1218 H,O. C= 67.27; H -6.67. CI7H,,O, requires C = 67.10 ; H = 6-57 per cent.According to the former view concerning the action of the ethereal salts of chlorofumaric and a-chlorocrotonic acids on those of P-ketonic acids, this substance is to be regarded as ethylic benzoyl-P-butylene- dicarboxylate. Its constitution, in the light of Claisen's researches on ketone-compounds, is to be represented by the formula C,H,* C(0H):y COOC,H,. CH,. CH:C COOC,H, This expression is confirmed by the determination of the refractive index, which was found to be n, = 1524 at 15" ; the molecular refrac- tion amounts, therefore, to 81.80, whilst the value calculated for the above formula is 81.53. Ethy lie McclonyZ-,B- bzLtyZeneti.icarbox~Zate, This compound is formed by adding 20 grams of ethylic acetone- dicarboxylate, and then 15 grams of ethylic a-chlorocrotonate, to a solu- tion of 2.3 grams of sodium dissolved in 50 C.C.of absolute alcohol, and by boiling the mixture on the water bath until it is no longer alkaline to litmus paper, The product of the reaction, isolated in the usual way, boils at 196-197" under a pressure of 10 mm. ; it is a328 RUHEMANN : &KETONIC ACIDS. colourless oil, having the density d 15"/15O = 1.1445, and its alcoholic solution is only faintly coloured by ferric chloride. Analysis gave values corresponding with the formula for ethylic malonyl-/3-bu tylenetricarboxylate. COOC,H,* CH,* CO*FH* COOC,H5. CH,. CH : COOC,H, 0.2471 gave 0.5190 CO, and 0,1566 H20. C = 57.28 ; H = 7.04. C1,H,,O7 requires C = 57.32 ; H = 7.00 per cent. The constitution of this compound, indicated above, is confirmed by its refractometric behaviour.The refractive index was found t o be nD = 1.472 at 15"; the expression iM amounts, therefore, to 76.76, whilst the formula C1,H,,O,: (OJ" requires 76.54. Action of Ammonicc.-If the ethereal salt is allowed to remain in con- tact with a concentrated aqueous solution of ammonia for several days, it disappears, and from the yellow solution, which! on exposure to the air, t,urns bluish-green, a crystalline solid separates ; this dissolves in boiling water, and, on cooling, comes down in colourless, striated, octa- gonal plates, which melt at 199-200", having begun to soften a few degrees before. 1L2- 1 (n2 + 2)d 0.2149 gave 0.4095 GO, and 0.1196 H,O. 0,0986 ,, C=51*54; H=6.18. 9.2 C.C. moist nitrogen at 19" and 765 mm.; N = 10.80. C1,H,,N,05 requires C = 51.56 ; H = 6.25 ; N = 10.93 per cent. The compound is therefore to be represented by one of the following f ormulE. II. CONH,* CH2-C'O*5JH*CONH, I. CH; C H : C*COOC,H, COOC,H,* CH,* CO*yH* CONH, CH,CH: C*CONH, CONH,. CH,* CO YH*COOC,H, CH,*CH :C*CONH, ' 111. The aqueous mother liquor of the compound melting at 199-200" con- tains, besides this substance, another crystallising in needles, the isolation of which could not be effected. This mixture has not a constant melting point, beginning to soften a t 165". I t s analysis leads to the same com- position, CllH,GNZ05, as was established for the substance crystallising in plates. 0*2020 gave 0,3790 CO, and 0.11 60 H,O. 0.2047 ,, The action of ammonia on the ethereal salt also gives rise to a third substance; this occurs in tho ammoniacal filtrate from the solid con- C = 51.17 ; H = 6.38 20 C.C.moist nitrogen at 18" and 758 mm.; N = 11.10.RUHEMAXN AND HEMMY : B-KETONIC ACIDS, 329 sisting of the two above-mentioned amides, and is precipitated either on acidifying the solution with hydrochloric acid, or on evaporatbg it. This compound is the diamido-acid, correaponding with one of the three isomeric ethereal salts symbolisecl above. The acid being insoluble in water and in alcohol, and only slightly solubIe in glacial acetic acid, is purified by decolorising its solution in ammonia mi th animal charcoal, and precipitating the filtrate with hydrochloric acid ; it is a grey, crys- talline powder which does not melt, but decomposes at about 270". The analytical data agree with the formula C,H,,N,O,. 0.2038 gave 0.3526 CO, and 0.0954 H,O. 0.2110 ,, C = 47.19 ; H = 5.20. C,,H,,N,O, requires C = 47.37 ; H = 5.26 ; N = 12.28 per cent. It may be mentioned that the research recorded in this paper is being extended to the study of the action of ethylic chlorofumarate and ethylic a-chlorocrotonate on the ethereal salts of other P-ketonic acids. Tn conclusion, I must express my thanks to Dr. G'. Wolf for the help he has given me in the analytical part of this work. . 22 C.C. moist nitrogen at 18" and 774 mm. ; N = 12.26. GONVILLE AND CAIUS COLLEGE, CAXBRIDGB.

ISSN:0368-1645    

DOI:10.1039/CT8977100323

出版商:RSC    

年代:1897

数据来源: RSC