RIONO-, DI-, AND TRI-CHLOHBCETYL CROUPS, ETC. 181 x IlI.-EJect of the Moiao-, DG9 and Tyi-chloracetyl Grozqjs o f i the Rotatory Power of Methylic and Etlzylic Glycerates a d Taytrates. By PERCY FRANKLAND, F.R.S., and THOMAS STEWART PATTERSON, Ph.D., Late Priestley Scholar in Mason University College, Birmingham. THE effect of attaching halogens to the asymmetric carbon-atom has been the subject of numerous researches in which chlorine or bromine is substituted for the hydroxyl group of an optically active compound. I n the earlier investigations of this nature, the substitution mas effected by the action of the halogen acid, with the result that the halogen compound obtained was invariably inactive. Thus, from I-malic acid and hydrobromic acid, Kekulk (Ann., 1864, 130, 25) ob- tained only inactive bromosuccinic acid ; from Z-mandelic acid and hydro- chloric and hydrobromic acids, Easterfield (Trans., 1891, 59, 71) obtained only inactive chloro- and bromo-phenylacetic acids ; similarly, from active ( I and d ) isopropylphenylglycollic acids, Fileti (J.p . Chem., 1892, 46, 562), by the action of hydrochloric acid, obtained inactive isopropylphenylchloracetic acid only. The uniformity of these results not unnaturally led to the impression that such intro- duction of the halogen atoms must necessarily be attended with racemisation, and even gave rise to a suspicion that possibly the mere difference in the four groups attached to the carbon atom was not in itself sufficient to cause optical activity (Hantzsch, Grundriss d. Xteceochenzie). The incorrectness of these views has been more recently dem0nstrate.I by Le Be1 (Bull.SOC. chim., [iii], 1893, 9, 674), and more especially by Walden (Ber., 1895, 28, 1297), who, by acting with the halogen compouiids of phosphorus on the ethereal salts of malic, tartaric, lactic, and mandelic acids, has obtained active ethereal salts of bromosuccinic, bromomalic, chloro- and bromo- propionic, chloro- and bromo-phenylacetic acids, whilst these results have been further extended by J. Wallace Walker (Trans., 1895, 07, 914) in respect of chloro- and bromo-propionic acid. I n the substitutions by chlorine and bromine referred to above, it is very noteworthy that the sign of the rotation is reversed by the introduction of the halogen, a result which is contrary to what takes place when substitution in the same compounds is made by most other groups. This circumstance led to the idea that there mas something anomalous in the rotatory effect of the halogen atom attached to the asymmetric carbon atom.It has, however, been shown by Walden (Bey., 1895, 28, 2766; 1896, 29, 133) that the change in sign in the case of the ethereal salts of d-chloro-182 FRANKLAND AND PATTERSON : EFFECT OF THE CHLORACETYL succinic acid obtained from the I-malic salt is due t o a most re- markable transformation, for on regenerating malic acid from the d-chlorosuccinic acid, it is d-malic, and not Lmalic, acid which is obtained, and a similar transformation has been shown to take place by Purdie and Williamson (Trans,, 1896, 69, 837) in passing from the lzvorotatory lactic to the dextrorotatory chloropropionic ether, the latter, on removal of the halogen, yielding the dextrorotatory lactic compound.It is thus evident that the chloro- and bromo-compounds redly corresponding to the tartaric, malic, and lactic compounds from which they are derivable, and in which the halogen is attached t o the same bond of tlie asymmetric carbon atom as that t o which the original hydroxyl group of the parent substance was united, have a rotatory power of the same sign as the particular parent substance in question. The above results all refer to the effect of uniting the halogen directly to the asymmetric carbon atom, and a t the time our experi- ments were commenced there existed, so far as we are aware, only a few isolated observations of Le Bel’s (Zoc.cit.) and of Walden’s on the rotatory effect of halogen-atoms not so directly attached. The follow- ing is the extent of the observations made by Le Be1 on this subject. Propylene glycol, CH,*CH(OH)*CH,*OH, u = - 1’ 57’ ( I = 22 cm.). Propylene glycol diacetate, CH,*CH(O~C,H,0)*CH2*O*C2H30, a = - 8 Propylene glycol monochlorhydrin, u == - 53‘ ( I = 22 em.). Propylene glycol dichlorhydrin, a = - 23’ ( I = 10 cm.). Propylene glycol chlorobromhydrin, CH,* CHBr*CH,Cl, a = - 38’ ( I = 10 cm.). Propylene glycol chloracetin, CH,* CH(O*C,H,O)*CH,Cl, u = -I- 1’ 18’ ( I = 22 cm.). Propylene glycol chlorochloracetin, CH,* CH(C2H2C10,)*CH2C1, a = + 49’ ( I = 10 cm.). Propylene glycol chlorobutyrin, CH,* CH(O*CO*C,H7)*CH,Cl, a= + 27’ ( I = 10 cm.).From the above it will be seen that propylene glycol chloracetin has iiearly the same rotation as propylene glycol chlorochloracetin, so that in this case the substitution of chlorine for hydrogen a t a point remote from the asymmetric carbon atom does not very materially affect the rotation. The observationswhich had been made by Walden (Zeit.phys%cbl. Chem., 1895, 17, 264) referred t o the rotation of some monochloracetyl- and monobromacetyl-malates, a full summary of which will be found in ft paper by one of us (Trans., 1896, 69, 122). Again, more recently still, since the work recorded in this paper (Z=22 cm.).GROUPS ON THE ROTATORY POWER OF GLYCERATES, ETC. 183 was performed, some compounds have been prepared by Guye and Chavanne (BUZZ.SOC. chim., [iii], 1896, 15, 177--195, 275-305) which have a bearing on the same subject. Amylic alcohol ........................ [ u]y"= - 4'52" [ a ] y = - 4-12' , , acetate ....................... [ a]tOo = + 2 -53 [ a ] F = +2'51 , , propionate .................. [ u]? = + 2.77 [a]"d;"= 4-2.68 , , monochlorace tate ......... [a]ip= + 3'44 [a]y= t-3'36 ,, dichloracetate ............ [a]i2= -t 2.77 [a]:o'= +2.65 ,, trichloracetate.. ............. [.I2: = + 2.71 [a]:'= + 2.58 It was with the object of extending this knowledge of the rotatory effect of the h dogen-substituted fatty acid radicles that our inve3tiga- tiou was uridertakeii, b u t before its completion the rebults of a some- what similar iuyuiry were published by Freundler (Bull. SOC. cl~im., [iii], 1895, 13, l055), mliohe experimrlits are, however, limited to an examiri &ion ot the ir,ethj lw, e t h y tic, propylic, aud is0 j u t ) lic salts of dimouochlora etyltartiLric acid.Our investigations, there1 ore, only overlay in the matter of the preparation and study of two single com- pounds, to which special attention will be directed later on. , , monocliloropropionate ... [ u]i2 = + 3 *03 I. TRICHLORACETYL DERIVATIVES. Pyepcwation of Tvichlomcetyl Cldoyide.-This was effected by utilis- ing Friedel's reactiou in the manner described by Friederici (Bey., 1878, 11, 1971). A mixture of 100 grams of trichloracetic acid and 150 grams of phosphoric anhydride was heated at about 200' in a Wurt'z flask of about 2 litres capacity and dry hydrogen chloride passed into the flask above the surface of the mixture.The lateral tube of the flask was connected with a U-tube surrounded with ice and provided with a tubulure below, passing into a small flask in which the condensed liquid was collected. Only slight charring took place, and a good yield of chloride mas obtained, but the process is slow, two or three days being required for the preparation of 60-70 grams. The chloride was fractionated, using a Hempel tube, and was ultimately obtained almost entirely free from phosphorus compounds. We adopted this method of preparation for all the three chloracetyl chlorides in consequence of its being the only one which yielded a product very nearly free from phosphorus compounds. Ethylic Di-trichZoracetyZgEycerate.-This was prepared by allowing 16 grams of ethylic glycerate (a, = - 11-47' in 100 min.tube at 12') to drop slowly into 130 grams of trichloracetyl chloride a t loo", the mixture being maintained at this temperature for about 2 hours, and frequently shaken, a method which waa adopted in the preparation of nearly a11 the other ethereal salts described in this paper. The product was theii184 FRANKLAND AND PATTERSON : EFFECT OF THE CHLORACETYL submitted to distillation under diminished pressure, the excess of tri- chlorncetyl chloride passing over at 45-50', a first fraction was collected at 198" and a second a t 198-205". The first fraction was again treated with trichloracetyl chloride, and on distilling as above a frnc- tion was collected between 200' and 205", and this was mixed with the 198-205" fraction of the first distillation.This mixture was then refractionated until the rotation of the product became practically constant. I n this way, 9 grams of substance, boiling a t 202' under about 15 mm. pressure, and with the oil-bath at 240", were obtained. The following chlorine determinations were made by Carius' method. 1. 0.7466 gave 1.4976 AgC1. Cl=49-65 per cent. 3. 0.5608 ,, 1,1354 AgC1. Cl=50.06 ,, 3 . 0.565'7 ,, 1.1360 AgC1. C1=49*67 ,, 4. 05200 ,, 1.0406 AgCl. C1=49*50 ., 5. 0.5651 ,, 1.1340AgCl. Cl=49*64 .. C,H,O,CI, requires C1= 50.1 1 ycr C C ~ I L . The rotation was determined a t the following temperatures. Temp. 12.5' 98 77 60 48 42.5 12.6 Observed rotation in 44 nim. tube. - 12.73" - 11-89 - 12.19 - 18.28 - 11.68 - 12.08 - 12.66 Density compared with water at 4".[.In LSI,,* 1.5502 - 18.66' 1.4438 - 18.39 - 176.6" 1.4702 - 18.38 - 178.7 1.4925 - 18.39 - 180.6 1.5060 - 18.39 - 181.9 1.5127 - 18.40 - 182.8 1.5502 - 18.56 - 186.1) The density determinations actually made were d 12'/4'= 1.5502. d 60'/4*= 1.4915. ~l 100°/4'= 1.4413. Methylic Di-tricl~rorncetylgZycernte.--Twenty grams of methylic gly- cerate (a= - 6.30' in 100 mm. tube at 13.3') were slowly added to an excess of trichloracetyl chloride at 1 loo, the heating being continued for several hours. The excess of trichloracetyl chloride was distilled off under diminished pressure, and a fraction (30 grams) passing over at 185-204'was repeatedIyfractionated,when 9 grams of the rnethylic salt distilling a t 199--200°, under about 15 mm.pressure, and with the oil-bath at 225', mere obtained. The chlorine in this was determined.GROUPS ON THE ROTATORY POWER OF GLYCERATES, ETC. 185 1. 0.7007 gave 1.4557 AgC1. 2. 0.6275 ,, 1.3087 AgCl. C!=51*59 ,, C1= 51.40 per cent. C,HGO,C1, requires C1= 5 1 a82 per cent. The rotation was determined at the following temperatures. liotation of Methylic Di-ti.ichloi.acety~~Z~cer~tte. Observed rotation Density compared T ~ X U ~ J . in 44 i i m ~ tube. with water at 4". [.ID [ 6 1 D 11.5" - 10*03O 1.6125 - 14-13' - 144.5" 98.3 - 10.07 1.4964 - 15-29 - 148.8 1 2 - 10.05 1.6118 - 14.1i - 144% The density determinations actually made were cl 1 17"/4' = 1 *6 122. d 50"/4O = 1.5582. d 100"/4" = 1.49112. 3thyZic ~~o?zo-ts.iciLZorncety~tai,trccte. --Thirty grams of ethylic tartrat u (aD = + 8-47", t = 13', I = 1) and 200 grams of trichloracetyl chloride, heated a t 120" for 3 hours as before, were subsequently distilled under diminished pressure ; the excess of trichloracetyl chloride passed over first ; a t 160°, what appeared to be unaltered ethylic tartrate wab collected, whilst the ethylic salt (40 grams) came over mostly at 190".After two refractionations, the boiling point was 195' (oil bath 230°, pressure about 16 mm.), and as the rotation had hardly been affected by the last distillation, the chlorine mas determined by Carius' method. 1. 0.5463 gave 0.6625 AgC1. C1= 30.00 per cent. 2. 0.5486 ,, 0.6635 AgC1. C1=29.92 ,, The substance was then again twice redistilled, the boiling point being 185' (oil bath 210", pressure about 16 mm.), and the final pro- duct again analysed.1. 0.5804 gave 0.7050 AgC1. C1= 30.05 per cent. 2. 0.6782 ,, 0.8220 AgCl. C1=29*98 ,, C,,K,,07CI, requires C1= 30.30 per cent. C,,H,,08Cl, ,, 01=42*48 ,, The -substance obtained was, therefore, ethylic mono-trichloracetyl- With this, the following polarimetric observations were made. tartrate.186 FRANKLAND AND PATTERSON : EFFECT OF THE CHLORACETYL Rotcction of Ethylic Mono-tric~loracetyltar2~~ute. Obsorved rotation Temp. in 44 mm. tube. 11 *6O + 9.37" 98.5 + 10.01 58-2 + 9.88 46.2 + 9-81 38.5 + 9.77 12.0 + 9.39 Density compared with water at 4". [ a ] , 161, 1.3963 + 15.25" + 134.5' 1.2981 + 17.53 + 147.2 1 *3446 + 16.70 + 143-6 1.3609 + 16.39 + 142.0 1.3744 + 16.16 + 140.9 1,3959 + 15-30 + 134.8 The density determinations actually made were Methylic Mono-trichZos.cccet~/Itartrc~€~. -Thirty grams of methylic tar- trate (aD = + 2-28', t = 16', E = l ) , and 150 grams of trichloracetyl chlor- ide, after heating a t 110" for two days, on distillation as before, pave st fraction at 180-210" which crystdlised soon after cooling.The crystals, after treatment with water to remove any unaltered rnethylic tartrate, were pressed between filter paper and dissolved in toluene. This solution, after drying with calcium chloride, was allowed t o crystallise, and the greater part of the substance remaining in solu- tion was deposited on adding light petroleum : 21 grams of crystalline substance were obtained. On recrystallisation from xyleue, the melting point was 'i9-80°,-and two Carius' determinations of the chlorine gave the following results.1. 0,4737 gave 0.6286 AgC1. 3. 0.5293 ,, 0.7015 AgC1. Cl=32*77 ,, d 11'/4' = 1 *3970. d 50'/4'= 1.3541. d 100'/4' = 1.2964. C1=32.83 per cent. C,H,O,UI, requires C1= 32.92 per cent. The substance obtained was, therefore, methylic mono-trichloracetyl- tartrate. The crystals of which the above analyses were made were recrystal- lised from hot xylene; after washing with a little xyleue, they were ground up, and the powder, washed several times by decantation with light petroleum, was collected and dried in a vacuum desiccator. Its melting point was found as before to be 79-80', and with it the following polarimetric observatioiis were made. C,,H,O,Cl, ,, C1=45.42 ,, h'otatiou OJ Metlylic ?I.iol~o-tricl~Zo~~cccetyltar~~ccte. Temp.in 44 mm. tube. with water at 4". c a 111 [SID 1 ooo + 6 ~ 2 9 ~ 1 -408 1 + 10.15* + 87.55' 62 + 5-92 1 a4536 + 9.25 + 81.53 51.5 + 6.77 1.466'i + 8.94 + 79.23 17 + 5.50 1.5083 + 8.29 + 74-82 Observed rotation Dciisity comparedGROUPS ON THE ROTATORY POWER OF QLYCERATES, ETC. 187 The density terminations actually made were d 17'14" = 1.5083. cl 50G/40 = 1.4696. d 1So/SG =1*5056. d 100°/40 = 1.4081. 11. D I c H LO RAC ETY L DERIVATIVES. Preparation of i)ichZoracetyl ChZoride.--This was prepared by passing dry hydrogen chloride over a heated mixture of 100 grams of dichlor- acetic acid and 150 grams of phosphoric anhydride. The action proceeds readily, the product being more rapidly obtained than in the case of the trichloracetyl compound ; there is, however, a considerable amount of charring and a quantity of gas, consisting almost exclusively of carbonic oxide, is given off.* Zthylic Di-dichIoracetylglyc~~c~te.-This was prepared in the usual way from 28 grams of ethylic glycerate (aD = - 11.40°, t = 23O, I = 1) and 200 grams of dichloracetyl chloride heated at 106" for two days, and then repeatedly fractionating.The crude product was washed with a warm solution of sodium carbonate, and extracted with benzene. The benzene solution was again washed with sodium carbonate, then several times with water, and after drying with calcium chloride, the beuzene was first distilled off under atmospheric pressure, the residue being distilled under diminished pressure. The final product (7 grams) thus obtained distilled at 203' (oil bath a t 250°, and under about 15 mm.pressure). The chlorine was determined by the Carius-Volhardt method. A good yield was obtained. (Walker and Henderson, Chem Netus, 71, 103, 205). 1. 0.2228 required 0.4236 AgNO,. C1= 39-71 per cent. 2. 0.1588 ,, 0.3011 AgNO,. C1=39.60 ,, C,H,,O,CI, requires (21 = 39.89 per cent. The following polarimetric observations were made. Observed rotation 'l'emp. in 44 inm. tube. 16.8" - 11.82" 35.1 - 12.17 46.5 - 12.31 59.7 - 12.41 99 - 12.66 16.8 -- 11 .ss Density con;l)ared with water at 4" [ a ] , 1.4667 - 18.32" 1.4446 - 19.15 1,4291 - 19-58 1.4129 -- 19.96 1.3669 - 21.05 1.4667 - 18.33 * The decoiupositioii may possibly be represented thus CHCI,*COOH = 2CO + 2HC1 CHCI,*COOH = CO, -I- C I- 2HC1 [&ID - 167.6" - 173.4 - 176.0 - 183.7 - 178.1 - 167.6 1 I I t,lii.; coiiiiectioii, i t Le meill ioiicd that Alauineni (A?>uZe/z, 1865, 133, 154) has show^ t h a t the silver salt, 011 I~cating, decoinposcs into cnlbonic oxide, carbonic anhydride, and silver chloride.188 FRANKLAND AND PATTERSON : EFFECT OF THE CHLBRACETYL The density determinations actually made were d 16*8"/4"= 1.4667.d 31*5'/4' = 1.4485. d 46*5"/4' = 1.4291. d 59.7"/4"= 1.4129. d 100°/4"= 1,3657. Metlqlic Di-dichIorcccet?/lgZycel.cLte.-FiEteen grams of methylic glycerate (a, = - 6*44O, t = 16*5', I = 1) and 170 grams of dichloracetyl chloride, heated a t 11OOfor three days, were distilled as before,and passed over chiefly (30 grams) at 200-210°. This distillate was shaken up with a warm solution of sodium carbonate and extracted with benzene, and the benzene solution was again washed with sodium carbonate solution and then with water ; after drying with calcium chloride, the benzene was distilled off under atmospheric pressure, and the residue under diminished pressure.On repeated fractionation, which did not appreciably affect the rotation, the final product passed over at 207" (oil bath 260°, 20 mm. pressure). The chlorine was determined by the Carius-Volhardt metbod. 1. 0.3515 required 0,6942 AgNO,. Cl= 41.24 per cent. 2. 0.3894 ,, 0.7672 AgNO,. Cl=41.14 ,, C,H,O,Cl, requires C1= 41.52 per cent. The following polarimetric observations were made. lZo t at ion of J l e thy ti c Di-d icldoi-ace t 9 1yZ y cei *a t e .Observed rotatioil Density compared Temp. in 44 min. tube. with water at 4". L a l o 100 - 10.76 1.4235 - 17.18 74.4 - 10.53 1.4553 - 16.44 55 - 10.32 1.4796 - 15*S5 40 - 10.05 1.4982 - 15.25 14.5 - 9-39 15" - 9.39" 15290 - - 13-96' La]" - 129.6" - 152.0 - 147.9 - 143.9 - 139.6 The density determinations actually made were d 20°/4" = 1.5228. d 40°/4" = 1.4982. t l 60"/4" = 1.4734. d 80"/4O= 1,4484. d 100°/4"= 1.4235. E'tlqlic Di-dicl~Zol.ucetyZtc~~~t~c~te.-Thirty grams of ethylic tartrate (aD = + 9*31°, t = ZOO, I = 1) and 180 grams of dichloracetyl chloride, heated a t 110" for three days, gave a product the chief portion of which, on fractionation, passed over at, 220-230" (oil bath 260°, 20 nini. pressure). This was shaken with a hot solution of sodium carbonate and ex- tracted with benzene, &c., as in the preparation of the corresponding The yield was 35 grams.GROUPS ON THE ROTATORY POWER OF GLTCERATES, ETC.189 glycerate (p.~.). The product, redistilled until the rotation was constant. boiled at 225' (oil bath 260°, about 15 mm. pressure). The chlorine was determined by the Carius-Volhardt method. 1. 0.1685 required 0.2648 AgNO,. C1= 32-88 per cent. 2. 0.1681 ,, 0,2625 AgNO,. C1=32.61 ,, C,,H,,O,Cl, requires C1= 33.18 per cent. The following polarimetric observations were made. Rot ci t i o n of Et h y lie D i-d ichlom ce t y E t ctr t 9 '(6 t e . Observed rotation Density compared Temp. in 92'35 mm. tube. with water a t 4". [.ID [ 6 1 D 16" + 81.28' 1.4137 + 16.30' + 154.7' 41.5 + 21.07 1,3845 + 16.48 + 154.2 54.7 + 20.92 1,3695 + 16.54 + 153.7 74 + 20.92 1.3468 + 16.82 + 154.5 l(J0 + 20.78 1.3171 + 17.08 + 154.7 The density determination's actually made were d 21°/4'= 1.4080.cl 40'/4' = 1.3862. d 60'/4' = 1.3635. d 80'/4' = 1.3397. d 100°/40= 1.3171, Methglic Di-dicl~lorucetgltartrccte. -T hirty grams of met hylic tartrate (a, = + 4.57, t = 16', E = 2) and 150 grams of dichloracetyl chloride, were heated a t 1 10' for two days, and the product fractionated as before ; the excess of acid chloride came over a t about 50', and the methylic salt between 170-220°, chiefly a t 180' (oil bath a t 215-250'). On refrac- tionating twice, some of the distillate crystallised spontaneously, and crystallisation was induced in the remainder by st,irring with water. The solid was purified by trituration with a solution of sodium carbonate, drying on porcelain, and recrystallisation from xylene, the crystals being washed with a little xylene and then with light petroleum.The melting point was 63.5-64'. A further quantity was recovered from the xylene solution by precipitation with light petroleum, the total amount being 8 grams. This was distilled, the boiling point being 220-221' (oil bath 260°, about 15 mm: pressure), and the distillate, which rapidly solidified, melted at 64-45', The chlorine was determined by the Carius-Volhardt method. 1. 0,2243 required 0.3801 AgNO,. 2. 0.2427 ,, 0.4117 AgNO,. C1=35~42 ,, C1= 35.39 per cent. CloH,oO,CI, requires C1= 35.50 per cent.. The following polarimetric observations were made.190 FRANKLAND AND PATTERSON : EFFECT OF THE CHrAORACETYT, Rotcction of Met?hglic Di-cEic~lo?.cccet2/Ztnl.tl.nte. Observed rotatioil Deiisity compared Temp.in 44 mm. tube. with water at 4". Call) [all) 19.2' + 7.93" 1.5056 + 11-97" + 115.9' 37-6 + 7.47 1.4827 + 11-45 + 109.7 48.2 + 7.26 1.4693 + 11.23 + 106.9 55.2 + 7-16 1 *46 065 + 11.14 + 105.7 98.5 + 6.80 1.4101 + 10.96 + 101.s The density determinations actually made were tl 19'/4O= 15058. d 54O/4"-7 1,4620. d 100°j40= 1.40853. 111. &/I: o NOCIILO RACET Y L D E R I v A T I VES. Preparuiion of Monochlorucetyl Chloride.-Considerably greater difi- culty was encountered in the preparation of this than in the case of either the di- or tri-chloracetyl chlorides, owing to the very large amount of charring which takes place when monochloracetic acid is heated with phosphoric I? nhy dride.The method ultimately adopted consisted in introducing into a Wurtz ff ask, of 2 litres capacity, 150 grams of phosphoric anhydride, followed by 100 grams of melted monochloracetic acid. The flask containing the mixture was then a t once heated in an oil bath t o about 200', a rapid current of dry hydrogen chloride being passed through. The prin- cipal source of danger is the choking up of the lateral tube by the charred mass, which has a tendency to become extremely voluminous. I n one experiment, 83 gmms of crude chloride were obtained from 100 grams of the acid. The chloride was fractionated by means of a Heinpel tube, and, after one distillation, was almost entirely free from phosphorus.We may mention that we avoided the ordinary methods of preparing monochloracetyl chloride, because, firstly, the chlorination of chloracetyl chloride might lead to the formation of some dichloracetyl chloride, and, secondly, the method of acting with the chlorides of phosphorus on monochloracetic acid yields a product containing phosphoriis com- pounds, which we were unable to remove by any available means. Instead of monochloracetyl chloride, we tried, however, the use of monochloracetyl bromide for acting on ethylic glycerate, but obtained a n ethereal salt containing some bromine, and this method mas, there- fore, abandoned. Etlhylic Di-~~zonoc?r,ZorucetyZgZ~ce~*~~e.-~eventeen grams of ethylic. glycernte (a, = - 11-49', t = 14*5O, I = 1) and 90 grams of monochlor- acetyl chloride mere heated a t 110' for two days.On fractionating, the principal product came over a t 200--205° (oil bath 235'. pressureGROUPS ON THE ROTATORY POWER OF GLYCERATES, ETC. 191 about 18 mm.); this was twice refractionated, the rotation being practically unaffected by the last distillation. The final product dis- tilled at 198' (oil bath 235O, pressure about 15 mm.). The chlorine was determined by the Carius-Volhardt method. 1. 0.1700 required 0,2058 AgNO,. C1= 25.28 per cent. 3. 0.5123 gave 0.5246 AgCl (gravim.). C1= 25.33 The following polarimetric observations were made. 2. 0,2034 ,, 0.2464 AgNO,. C1=25.29 ,, ,, C,H,,O,Cl, requires C1= 24.74 per cent. Rotation of Etlzylic Di-nzonoc~Zoi.cccet?/lglyce. Observed rotation Density compared Temp.in 44 min. tube. with water at 4". [ a ] , 161r) 100' - 12.34' 1.2704 - 22.08' - 170.8' 66 - 11.88 1.3089 - 20.52 -- 162.0 40 - 11.13 1.3402 - 18.87 . - 251.4 15 - 10.12 1.3693 - 16.80 - - 136.6 The density determinations actually made were d 16'/4'= 1.3681. (1 8Oo/4O= 1.2922. d 5Oo/6O = 1.3279. d 100°/4' = 1.2704. Methylic Di-~?~oizocl~loiwacetylglycerate.-The methylic glycerate used mas derived from 35 grams of crystallised calcium glycerate. The rotation of the methylic salt was aD = - 6*24', t = 14*5O, I = 1. This methylic glycerate was heated at 110' with 80-90 grams of monochloracetyl chloride for two days. On fractionating the mixture, 21 grams of product were obtained boiling at 190-205O (oil bath 230°, pressure about 15 mm.); this was successively washed with solution of sodium carbonate and with water, extracted with benzene, &c.(see p. 187). On fractionation, the main portion passed over at 197' (oil bath 235", pressure about 15 mrn.). This, when redistilled, exhibited the same boiling point and practically the same rotation. The chlorine was determined by the Carius-Volhardt method. 1. 0,2044 required 0.2570 AgNO,. 2. 0.5623 gave 0.5977 AgCl (gravim.). The following polarimetric observations were made. C1= 26.26. C1= 26.30. C,H,oO,C)l, requires C1= 26.01 per cent.192 FRANKTJANT) AND PATTERSON : EFFECT O F THE CHTJ~RACETYTJ Rotation of Metlq Zic Bi-monoclhy Zorncet$'gZ~cerccte. Observed rotation Density compared Temp. in 44 inm. tnbe. with water a t 4". r a1LI E61D 100' -10.49" 1.3251 - 17.99" - 140.8 40 - 9.04 1.3954 - 14-72 - 119.3 29.2 -8.68 1.4099 - 13.99 - 114.1 15 -- 8.10 1,4263 - 12-91 - 106.1 65 - 9.76 1.3662 - 16.24 - 129.7 The density determinations actually made were d 17"/4"=1*4240.d 40'/4"= 1.3954. d 60°/4"= 1.3722, d 80°/4'= 1.3480. d 100"/4"= 1.3251. This substance subsequently crystallised spontaneously, and tho solid melted at 43-44'. Ethylic Di-monochlomcetyltartrute.-A mixture of 15 grams of ethylic tartrate (aD= + 8-77", t = 16", I = 1) and 80 grams of monochloracetyl chloride was heated a t 110" for three days, and then fractionated as before until the rotation was constant. The boiling point of the final product was 217" (oil bath 245", pressure about 15 mm.). The chlorine mas determined by the Carius-Volhardt method. 1. 0.2073 required 0.2011 AgNO,.2. 0.5428 gave 0.4418 AgCl (gravim.). The following polarimetric observations were made. (71 = 20.25 per cent. C1= 20.13 per cent,. C,,H,,O,Cl, requires C1= 19.78 per cent. Motation of Ethylic Di-molzocl~loracet~~ta~trccle. Observed rotation Density compared Temp. in 44 mm. tnbe. with water a t 4". Caln E61 100" + 6.44' 1.2394 + 11.81" + 96-84' 74.5 + 5.89 1.2667 + 10.57 + 87.93 49.5 + 5.29 1,2935 + (1.29 + 78-42 41 + 5.11 1.3026 + 8.92 + 75.58 15.5 + 4.33 1.3306 + 7.40 + 63.59 The following were the density determinations actually made. d 1S0/4" = 1.3279. d 40°/4" = 1.3040. d 6Oo/4O = 1.2823. d 80°/4" = 1.2603. d 100'/4" = 1.2394. After the above results had been obtained, we became aware of the fact t h a t methylic, ethylic, propylic, and isobutylic di-monochloracetyl- tartrates had already been prepared by Freundler (Bull.soc. chim., 1895, [iii], 13, 1055-1063). The following figures are given by him for the ethylic compound. B. p. 195-197"(12 mm. pressure), densityat 15O= 1.311 [a];"= + 9.4".GROIJYS ON THX ROTATORY POWER OF GLYCERATES, EN. 193 The specific rotation is thus higher by 2' than that found by us for the same temperature, whilst the density and boiling point are slightly lower. In consequence of this discrepancy, the preparation of this com- pound has been repeated by one of us in conjunction with Dr. Turnbull, the results being recorded in the paper which follows this. Methylic Di-n,aonochZosacet?lZtartl.ute.-From 20 grams of methylic tartrate (a, = + 4*5'i0, t = 16', 1 = 2) and 130 grams of monochloracetyl chloride heated at 110" for 2 days, 30 grams of product were obtained, distilling between 220" and 235" (oil bath 260°, pressure about 15 mm.).This solidified when triturated with a solution of sodium carbonate, and, after drying on porcelain, was crystallised from toluene, the crystals washed with light petroleum and then distilled. The boiling point was 217' (oil bath 260°, pressure about 18 mm.), 15 grams of this purified product being obtained, The substance crystallises from toluene in large, truncated pyramids; the melting point was 55'. The chlorine was determined by the Carius-Volhardt method. 1 0,2047 required 0.8092 AgNO,. C1= 21.34 per cent. 3. 0.2013 ,, 0.2059 AgNO,. Cl=21*36 ,, Cl,Hl,08C1, requires C1= 21.45 per cent.The following polarimetric observations were made. Rotatioiz of XethyZic l).i-1,ionochlorclcetyltara.ate. Observed rotation 'i'eiup. in 44 mm. tube. 100" + 1 ~ 5 0 ~ 75.3 + 0.76 54.7 + 0-25 43.3 - 0.05 33.6 - 0.16 14 - 0.50 Density compared with water at 4". c a10 L-510 1,3264 + 2-57" + 21-46" 1.3547 + 1.27 +10.80 1.3784 + 0.41 + 3.53 1.3915 - 0.08 - 0.70 1.4026 - 0.26 - 2-25 1.4250 - 0.80 - 6.98 The following were the density determinations actually made. d 19'/4'= 1.4193. d 40'/4" = 1 *3953. d 60°/4' = 1.3722, d 80°,'40 = 1.3492. d 100"/4"== 1.3264. Methylic di-monochloracetyltartrate has also been prepared by Freundler (loc, cit.), who describes it as an extremely syrupy liquid distilling a t about 187--190' (14 mm. pressure) and of density 1.409 a t 18'.The rotatory power hegives as polarimetric results which are, therefore, even more at variance with ours than in the case of the corresponding etbylic compound reFerred VOL. LXXIII. 0194 FKANKLAND AND PATTERSON : EFFECT OF THE CHLORACETYL ho above. His density is distinctly, and his boiling point considerably, lower than ours. I n consequence of this marked discrepancy, the preparation of this substance has also been repeated with some modifications by one of us in conjunction with Dr. Turnbull, and the results are recorded in the paper which follows this. M. Freundler has determined also the molecular weights of the methylic and propylic salts of di-monochloracetyltartaric acid by the cryoscopic method, using benzene and ethylenic dibromide as solvents, and we may take the+ opportunity of pointing out that he gives throughout an erroneous theoretical value for the molecular weight of each of these ethereal salts.Thus for the methylic di-monochloracetyl- tartrate he makes all his calculations on the basis of the true mole- cular weight being 431 instead of 331, and in the case of the propylic compound he uses the molecular weight 487 instead of 387. In~~uenck ~f tlbe CMomcetpl GTOUPS 0% t?Ae PlqsiccbI Ps*opes.ties. 1. An examination of the results recorded in the preceding pages shows that the introduction of two monochloracetyl groups (a) Increases the lsevo-rotation of methylic and ethylic glycerate, the effect being very similar to, but slightly greater than, that produced by the introduction of two acetyl groups, thus Methylic glycerate ................................. [a]?=- 4.80" ,, diacetylglycerate ........................ [u]:"= - 12-04 ,, dimonochloracetylglycerate .........- 12'91 Ethylic glycerate ................................... [ a]i6"= - 9'18 dimonochloracetylglycerate ........... [ a ] r = - 16.80 ,, diacetylglycerate ........................ [ u ] ~ " = - 16.31 ), ( b ) Considerably reduces the dextro-rotation of methylic tartrate, and barely increases that of ethylic tartrate ; the effect on the latter is, in fact, hardly appreciable. I n this respect, the effect of the two monochloracetyl groups resembles, although it is far inferior to, that produced by the introduction of two acetyl groups. Thus two acetyl groups greatly reduce the dextro-rotation of methylic tartrate, and very considerably reduce that of ethylic tartrate, Rlethylic tartrate ........................... [a]?= + 2-14' (liquid), ,) diacetyltartrate ...............[a]:5n= - 15.1 (inabsolute alcoholic solution) ), di-moiiochloracetyltartrate.. , [a - 0'64 (liquid). Ethylic tartrate ........................... [a f 7 '66" di-monochloracetyltartrate ... [uEoo= i- 7-67" , , diacetyltartrate.. ................ t = 25", I = 1, a= + 5" ,, All three ethylic salts were examined in the liquid state.GROUPS ON THE ROTATORY POWER OF GLYCHRATES, ETC. 195 I n this respect, our results are in direct opposition t o those of M. Freundler, who finds that the introduction of the two mono- chloracetyl groups slightly but appreciably increases the dextro-rotation of both methylic and ethylic tartrates respectively.We would remark in this connection that we have obtained both the methylic and ethylic di-monochloracetyl tartrates in a crystalline state,"whilst M. Freundler has only handled them in the liquid condition. The diminution in the dextro-rotation of methylic and ethylic tartrate effected by the introduction of the two monochloracetyl groups is much more conspicuous if the rotations at a high temperature are taken into consideration, thus Methylic tartrate ................................... [a];O"= + 5-99" di-monochlorace t y 1 tartrate ......... [.I;;" = + 2-57 , , Ethylic tartrate .................................... [ a]!'o'= + 13-29 ,, di-monochloracetyltartrate ............ [u]~~'= +11'81 2. Similarly, the above results show that the introduction of two dichloracetyl groups (a) Jncreases the laevo-rotation of both methylic and ethylic glycer- ate, the laevo-rotation of these di-dichloracetylglycerates being, how- ever, only slightly greater than the corresponding di-monochlor- acetylglycerates ; indeed, this relationship only holds good at low temperatures, for a t high temperatures the lzvo-rotation of the di- monochloracetylglycerates slightly but distinctly exceeds that of the corresponding di-dichloracetylglycerntes. Thus- [ a ] y [ a ] y Methylic glycerate ........................ - 4.80" - 8'31"t (calculated).,, diacetylglycerate ............... - 12'04 - 19 '24t (calculated). , , di-monochloracetylglycerate.. - 12'91 - 17 '99 ,, di-dichloracetylglycerate ......- 13'96 - 17'18 Ethylic glycerato ........................... - 9.18 - 12-55? (calculated). ,, diacetylglycerete ............... - 16'31 - 23'09t (calculated). , , di-dichloracetylglycerate ...... - 18'20 - 21.1 ,, di-monochloracetylglycernte.. . - 16 *80 - 22.08 * See the next paper. .t. I t should be pointed out that these values of [aID at 100" have been calciilated for methylic and ethylic glycerates and diacetylglycerates from the materials given in the papers by P. Frankland and MacGregor (Trans., 1893, 63, 1415 ; Trans,, 1894, 65, 754 ; Trans., 1894, 65, 768). 'l'hese materials enable the observed rotation, aD, to be extrapolated for loo", whilst the density for looo has been cal- culated by means of the average decrement in density, 0*0012211, for la rise in temperature, this average decrement having been obtained from density observations made on ethylic mono-trichloracetyltnrtrate, methylic di-dichlor:icctyltnl.tl.rrtc, tehylic di-dichlornceltylgycerate, and nietliylic di-trichloracetylglycerate.0 2196 PRANKLANI) hN1) lJATTEKSON : EFFECT OF THE CHLORACETYL ( b ) Very greatly increases the dextro-rotation of both methylic and ethylic tartrate, thus :- [ a]:O" Methylic tartrate ..................... + 2.14" , , di-dichloracctyltartratc + 11 '9 Ethylic tartrate ........................ + 7.66 , , di-dichloracetyltartrate ... + 16 *3 The rotation of these di-dichloracetyltartrates is. comparatively insensitive to temperature, the dextro-rotation of the et hylic compound increasing but slightly with rise of temperature, whilst that of the methglic compound very slightly declines under the same circum- Ytances.But even if the rotations a t 100" be compared, the introduc- tion of the two dichloracetyl groups effects a large increase in the dextro-rotation of both methylic and ethylic tartrate. Thus [~l;;uO Methylic tartrate .................... t 5.99" ,, cli-dichloracetyltartrate + 10.0 Ethylic tartrate ........................ + 13'29 ,, di-dichloracetyltartrate ... + 17'08 The effect on the dextro-rotation of methylic and ethylic tartrate produced by the introduction of the two dichloracetyl groups resembles that produced by the introduction of two phenacetyl groups, Thus Methylic di-phenacetyltartmte ...... + 14.5" (Freundler), Ethylic ...... [a];""= '15.3 ,, ,, 3.The introduction of two trichloracetyl groups was only found possible in the case of the glycerates, both methylic and ethylic tartrates yielding only monacidyl derivatives, The introduction of the two trichloracetyl groups has the effect of (a;) increasing the laevo-rotation of the methylic glycerate to a greater extent than the introduction of two dichloracetyl groups. This is, however, only the case at low temperatures, for the rotation of methylic di-trichloracetylglycerate, being but very slightly increased by rise of temperature, the laevo-rotation of methylic di-dichloracetyl- glycerate at 100" is markedly greater than that of methylic di-trichlor- acetylglycerate at this temperature. Thus at 100' the laevo-rotation of methylic glycerate is most increased by the introduction of the two monochloracetyl groups, and least by that of the two trichloracetyl groups.The relative effects on the laevo-rotation of ethylic glycerate pro- duced by the introduction of these several groups is exactly similar, The rotation of ethylic di-trichloracetylglycerate is almost perfectlyGROUPS ON THE ROTATORY POWER O F GLYCERATES, ETC. 197 insensitive to temperature, but, if anything, rise of temperature causes diminution in lavo-rotation. [a1;50 [ u ~ y Methylic glycerate ..................... - 4.80" - 8-31"' (calculated). ), diacetylglycerate ............ - 12.04 - 19-24" (calculated). ,, di-monochloracetylglycerate - 12-91 - 17.99 ,, cli-dichloracetylglycerate ... - 13.96 - 17-18 ), di-trichlorncetylglycerate - 14.2 - 15.3 Ethylic glycerate ........................- 9-18 - 12.55" (calculated). ,, diacetglglycerate ............ - 16'31 - 23.09" (calcnlated). , , di-monochloracetylglycer~te - 16.80 - 22'05 ,, di-dichloracetylglycerate ... - 18 -20 - 21 '1 ), di-trichloracetylglycerate . - 18.7 - 18'4 It is interesting t6 compare with the above the rotation of the diphenacetylglycerates, of which only the methylic compound has been prepared by one of us (Trans., 1896, 69, 111). Nethylic diphenacetylglycerate [a31D5'= - 16'0" 9 , 9 9 [ u ] ~ " " ~ = - 13.4 From these figures it will be seen that, in rotatory effect, the phen- scetyl group differs even slightly more from the ncetyl group than does the trichloracetyl group. 4. The introduction of a single trichloracetyl gronp into methylic and ethylic tartrate respectively produces a change in their rotation very similar to that which is effected by the introduction of two dichloracetyl groups into these same compounds, thus [a]$" [ a];oop Methylic tartrate ................................ + 2'14" -t 5 *99" ,, mono-trichloracetyltartratc......... + 8.4 + 10.15 ,, di-dichloracetyltartrate'. .............. + 16'3 + 17'08 In this connection, it is worthy of note that the introduction of n single monochloracetyl group? produces an effect closely resembling that which attends the introduction of the trichlorncetyl group, thus , , di-dichloracetyltartrate ............ + 11 -9 -i- 10'9 Ethylic tartrate.,. ............................... + 7 *6G + 13'29 ,, inono-trichloracetyItartrate .........+ 15.5 -i- 17.6 [a]:')" [ a]:wp"" EthyIic mono-monochlorncetyltnrtrate (slightly impure) -k 11 *44" + 17'32" and, as so frequently pointed out above, any preponderating influence of the di- and tri-chloracetyl groups as compared with that of the monochloracetyl group tends to become equalised at a high temperature. 5. The influence which the several groups under consideration in this paper exercise on the molecular deviation ([S],) may be suinmarised in the following tabular statements. * The footnote on p. 195 applies also here. 1. See 1'. 204, i n nest paper,198 MONO-, nr-, AND TRI-CHLORACE'I'YL GROUPS, ETC. I6 Differences Methylic glycerate .......................... .., diacetylglycwate ............... ,, di-monochloracetylglycerate ... , , di-dichloracetylglycerate ......,, di-trichloracetylglycerate ...... - 145 1 Ethylic glycerate ........................... - 52.8" ,, diacetylglycerate .................. - 108'2 I '':" } 84.2 113.2 ,, di-monochloracetylglycerate ... - 137 28 } 1134.2 29 ,, di-dichloracetylglycerate ...... - 166 ,, di-trichloracetylglycerate ...... - 187 } 21 [ 6 1150 Differences Methylic tartrate .............................. + 13" , , diacetyltartrate .................. , , di-monochloracetyltartrate ... ,, di-dichloracetyltartrate ......... , , niono-trichloracetyltartrate ... + 73 } - 43 ,, di-monochloracetyltartrate ...... i- 63 1 - ,, di-dichloracetyltartrate ........... + 155 1 +92 ,, mono-trichloracetyltartrate ...... -t 135 } -20 .............................. , , diacetyltartrate ..................... unknown + 4 9 0 ~ - Ethylic tartrate The relationship between the rotations of the several compounds we have investigated, and the influence of temperature on the rotation of each, is best shown by means of the diagrams, pp. 199, 201. From the diagram p. 201, it will be seen (a) That the specific rotations of methylic di-monochloracetyl- glycerate and methylic di-dichloracetylglpcerate are identical at 62", the rotations of the corresponding e t hylic compounds becoming iden- tical at 53". ( 6 ) That tbe methylic di-dichloracetyIglycerate and di-trichloracetyl- glycerate have an identical specific rotation at 21", the corresponding ethylic salts having also an identical specific rotation a t 2 2 O . (c) That the specific rotations of the methylic di-trichloracetyl- glycerate and di-monochloracetylglycerate become equal at 379 the rotations of the corresponding ethylic compounds, becoming equal 8.t almost exactly the same temperature, namely, at 35". Thus it would appear that the influences which lead to an equal degree of asymmetry, in the case of the two methylic salts, are condi- tioned by the same, or nearly the same, temperature as conditions an equal degree of asymmetry in the case of the two ethylic compounds, MASON UNIVEKSITP COLLEGE, BIRMINQHAM.199 InJuence of Tenapemture 012 the Moleculcw Deviation of the Compounds FRANKLAND AND PATTERSON. 3- 15 + 10 + 5 - 51 .- l o ( described. 10' 20" 30" 40" 50" 60" 70" 80" 90" 16 Temperature.199 InJuence of Tenapemture 012 the Moleculcw Deviation of the Compounds FRANKLAND AND PATTERSON. 3- 15 + 10 + 5 - 51 .- l o ( described. 10' 20" 30" 40" 50" 60" 70" 80" 90" 16 Temperature.201 FRANKLAND AND PATTEMON. In@uence of Tempemturs on the Xpc;fic Rotcction q? the Compounds + 15 -t- 10 + 5 ye 0 Y s 2 -* u la 5 $i - 5 - 10 - 15 - 20 10' 20' 30" 40' 50" 60' 70' 80" 90' 100' Z'emperrature.