CONDENSATIONS OF CYANOHYDRINS. PART 11. 933

LXXX1X.-Condensations of Cyanohydrins. Part 11. The Condensation of Chloralcyanohydrin with Chloral Hydra te and with Bromal Hydrate .

By HORACE LESLIE CROWTHER (Priestley Research Scholar of the University of Birmingham), HAMILTON MCCOMBIE, and THOMAS &OLD READE.

IN 1874 Wallach (Annden, 1874, 173, 297) showed that by the action of potassium cyanide on chloral there was produced, not only the normal cyanohydrin, which melts a t 61°, but also a colour- less solid, which melts a t 123O. This substance was produced by the action of potassium cyanide on chloral hydrate in either benzene or water, the chloral hydrate being present in excess of that re quired for the production of the normal cyanohydrin. Wallach found that this second compound was insoluble in water (whilst the normal cyanohydrin is readily soluble), and that it was unchanged after treatment with boiling water. By dry distillation of the substance, chloral and chloralide (I) were obtained. Strong acids decomposed the compound completely, and steam distillation had

(1.) the same effect. When the substance was heated with sodium hydroxide, chlorofarm and ammonia were produced. The mean of the analytical figures obtained for the substance was in fair agree- ment with the formula C,H,O,NC~, although the discrepancies between the individual analyses wer6 quite considerable.

Cech (Ber., 1876, 9, 1020) criticised these analytical rwults, show- ing that either of the formuh C,H,O,NCI, or C7H,0,NC1, would agree equally well with Wallach’s figures; and, finally, as the result of his own analyses, Cech adopted the second formula, and gave the compound the name trichloralcyanohydrin, (CCl,*CHO),HCN. Beyond the work of these two investigators, no attempts seem to have been made to elucidate the constitution of this compound. Its further investigation was undertaken because it was considered not unlikely that its constitution might be somewhat similar to those of the dehydration products of anisaldehydecyanohydrin and cinnamaldehydecyanohydrin, described by McCombie and Parry in Part I of this series (T., 1909, 95, 584).

It was evident from the researches of Wallach that the com- pound was not a true cyanohydrin, for it was unchanged by boil- ing with water, and did not yield the corresponding amide or acid

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934 CROWTHER, McCOMBlE, AND READE :

under any known conditions. Hence the presence of a cyanogen group in the molecule was scarcely conceivable, and all formulae containing such a group were rejected. For similar reasons, all formulx representing the substance as an amide had t o be abandoned.

By the action of strong mineral acids on this compound, complete decomposition took place (M7allach, Zoc. c i t . ) , the products being, presumably, chloral ahd the ammonium salt of the mineral acid. It was found, however, that, if the compound was boiled vigorously f o r ten minutes with a mixture of concentrated hydrochloric acid and glacial acetic acid, and the solution then cooled in ice, chloral hydrate and cliloralide (I) were obtained. Thus the compound must be related to chloralide in some simple way, and this con- clusion finds further suppor_t in Wallach's observation that chloral and chloralide are produced on distillation.

Whereas this method of degradation showed that the chlorine atoms were still present in the form of three trichloromethyl groups (CCl,.), and also accounted for all three oxygen atoms of the com- pound, it threw no light on the state of combination of the nitrogen atom. Some information on this point was obtained from the acyl derivatives of the compound. It became a matter of great import- ance to determine whether the acyl group was attached to an oxygen atom or to a nitrogen atom. Sodium carbonate in the presence of water and alcohol had no action on these acyl deriv- atives, and hydrolysis in the presence of mineral acids did not result in the elimination of the acyl group. The conclusion that the acyl group has displaced a hydrogen atom attached t o the nitrogen atom is theref ore unquestionable. Moreover, only one atom of hydrogen in the molecule is capable of being displaced by acyl groups, all attempts t o prepare polyacyl derivatives, even when a large excess of the reagent was employed, resulting in the forma- tion of the monoacyl derivative alone.

All these experimental facts connected with this compound can find complete expression only by a heterocyclic ring formula, in which the nitrogen atom and two of the oxygen atoms are present as members of the ring, th? three trichloromethyl groups forming side-chains attached t o three of the carbon atoms in the ring. Further, since in chloralide one oxygen atom is united to an atom of carbon t o form a carbonyl group, and the other two oxygen atoms form part of the ring, i t seems reasonable to adopt a similar dis- position of the oxygen atoms in the compound C,H,O,NCl,. Theoretically, the following three formulae become possible as com- plying with these conditions :

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CONDENSATIONS OF CYANOHYDRINS. PART 11. 935

CCI ,*CHmCO*NH b I

CO*CH(CCl,)*N H b I I I

CCI b H-0- AH *CCI 3 CCl,*CH--0-CH- CCI, (11.1 (111.)

0 - C W N H

I I CCI3*CH

~.CH(CCI,)-CH*CCJ, (IV. 1

These three formulae all explain the formation of monoacyl deriv- atives, and also the production of chloralide, although formula I1 explains that reaction better than either I11 or IV.

If the compound were represented by formula 111, then it would be a secondary amine; but all attempts to obtain a nitroso- amine failed, and all efforts t o prepare salts of the substance with acids resulted in decomposition and the formation of the ammonium salts of the acids employed. These reactions led t o the rejection of formula 111.

Formula IV is rejected also, because it seems impossible to ex- plain the formation of such a compound by the action of potassium cyanide on chloral hydrate. The authors are led, therefore, to the adoption of I1 as the formula of the compound produced when potassium cyanide acts on excess of chloral hydrate. With regard t o the name of this compound, it has been decided to call the parent

I 6

CH,-CH,*NH 5

, 1 : 3 : 5-dioxazseptan. I I

I substance, 10

2 CH,-0-CH, 4 3

The seven-membered heterocyclic ring in this case is indicated by the word “septan,” since heptane is reserved f o r those seven- membered rings in which there are seven carbon atoms. If this nomenclature be employed, compound I1 would be called 6-keto- 2 i 4 : 7-tri-(trichloromethyl)-l : 3 : 5-dioxazseptan.

The reaction between potassium cyanide and excess of chloral hydrate is explained as follows : normal chloralcyanohydrin is formed first; this then condenses with two molecules of chloral hydrate to give rise t o the dioxazseptan derivative. The momentary formation of trichlorolactamide, NH,*CO*CH(CCl,)*OH, is assumed as an intermediate step, but i t may be that this intermediate com- pound is not produced, but that the cyanohydrin coiidenses immediately with two molecules of chloral hydrate to form the cyclic compound 11. A good example of a similar condensation is furnished by the formation of chloralbenzamide,

CCI,*CH(OH)*NH*COPh,

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936 CROWTHER, McCOMBlE, AND KEADE :

by the action of hydrogen chloride on a mixture of chloral hydrate and benzonitrile (Pinner and Klein, Ber., 1878, 11, 10). In favour of this explanation of the reaction between potassium cyanide and chloral hydrate is the experimental fact that chloral- cyanohydrin in the presence of excess of chloral hydrate and potassium hydroxide gave a 50 per cent. yield of the crude dioxaz- septan compound. This niethod of preparation has also been ex- tended to the condensation of chloralcyanohydrin (1 mol.) with brornal hydrate (2 mols.), resulting in the forination of 6-keto-7- trichloromethyl-2 : 4-di-(tribromomethyl)-l: 3 : 5-dioxazseptan (V). By hydrolysing this compound with acid, there resulted the tri- bromoet,hylidene ester of trichlorolactic acid (VI). From this it

CCI,*CH CO-NH l) I

I I CBr,* CH--0--CH-C Br,

(V. 1 (VI. 1 follows that the carbon atom of the cyanogen group has remained attached to the chloral residue.

It is interesting to notice that no condensation product could be obtained from normal bromalcyanohydrin and excess of chloral hydrate in the presence of potassium hydroxide. Further, bromal hydrate, when treated with potassium cyanide, even when the bromal hydrate was in considerable excess, gave only the normal cyanohydrin.

The formulation of the product produced by the action of potassium cyanide on chloral hydrate as 6-keto-2 : 4 : 7-tri-(trichIoro- methyl)-1 : 3 : 5-dioxazseptan received further support when the benzoyl derivative was subjected to the hydrolysing action of hydro- chloric acid in alcoholic or acetic acid solution. The parent sub- stance, by this reaction, yields chloralide and chloral hydrate, but the compound is rendered much more stable when the hydrogen atom attached to the nitrogen is replaced by the benzoyl group, yielding VII. When this compound is hydrolysed by hydrochloric

CCI *6H c"0 ~ B z I CCl3*CH*CO*NBz*CH*CC1~

CCI ,*bH--O-CH*CCI, l o I AH bH 2 3 4

(VIT.) (VIII.)

acid, the change which takes place can be represented by the following equation :

C7€€,O,NCI,*CO*C&H, + 2HzO = CC&*CH(OH), + @,H40,NCl6*CO= C6H,,

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CONDENSATIONS OF CYANOHYDRINS. PART 11. 937

One molecule of chloral hydrate was removed from the molecule, and the benzoyl group remains in the portion which contains the other six chlorine atoms. The union between carbon atoms 6 and 7 seems to be a very stable one, and, taking this into consideration, on examining formula V I I it is seen that there are two ways in which a chloral residue may be eliminated from the compound, namely, by removing the chloral residue which contains carbon atom 2 or carbon atom 4. I n the former case there should result a com- pound (VIII) in which there are two hydroxyl groups; in the latter case there would be produced a compound (IX) in which there is only one hydroxyl group. The compound which was actually produced by the hydrolysis was found to be unstable, and the analytical figures obtained from it were inconsistent,

CCl,* Y H O CH(CCl,)*CO*NHBz O H

(1x0) but if the substance was converted into an acetyl or a benzoyl derivative stable compounds were obtained, which were found t o be monoacyl derivatives. Further, all attempts to pre- pare diacetyl or dibenzoyl derivatives failed. From this it follows that the product of hydrolysis of the benzoyl derivative of 6-keto- 2 : 4 : 7-tri-(trichloromethyl)-l : 3 : 5-dioxazseptan is &trichloro-a-(P'- trichloro-a'-hydroxyethoxy)-propionobenzamide (IX). On treat- ment with sodium carbonate or sodium hydroxide this compound dissolves, and, on acidification, a substance is precipitated, the analysis of which corresponds with the formula C5H2O2NCl5. The action of sodium hydroxide can be represented by the following equation :

C5H40,NeCO*C6H, + 3NaOH = C6H,*CO2Na + NaCl + 3H,O + C,H02NC1,Na.

The net result of this action is the removal of the benzoyl group and the elimination of the elements of hydrogen chloride and of water. Ths resulting compound, C,H20,NC1,, is stable towards bromine or permanganate; hence there is no double bond present in the molecule. On examining formula IX to see how hydrogen chloride could be eliminated so that a saturated derivative results, it is seen that there are present two CCl,-groups from which chlorine could be eliminated in the form of hydrogen chloride, and, in order to determine which of these groups lost a chlorine atom, recourse was had t o the condensation product of chloralcyano- hydrin with bromal hydrate (V). This compound was converted into the benzoyl derivative, the latter was hydrolysed with hydro- chloric acid, and the product was treated immediately with sodium carbonate; the resulting compound, on analysis, was found t o have

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938 CROWTHER, McCOMBIE, AND READE :

the f ormula C,H,O,NCl,Br,, that is, hydrogen chloride, and not hydrogen bromide, had been eliminated. From this result, by analogy, i t follows that from compound IX chlorine has been eliminated from the CC1,-group, which is attached t o the carbon atom adjacent t o the CO-group; in other words, the compound resulting must have the constitution X, namely, 4: 4-dichloro-3: 5- oxido-5-trichloromethyl-2-pyrrolidone,

/ C V C O

o< JCI, I \ I pH c-

I CCI,

(X. 1 and the analogous compound prepared from the bromal derivative must have the formula XI. Both these compounds (X and XI) are easily dissolved by alkalis, and this ready solubility must be ascribed t o the presence in the molecules of an NH-group between a CO-group and a carbon atom to which are attached strongly electronegative groups.

A further interesting reaction of 6-keto-5-benzoyl-2 : 4 : 7-tri- (trichloromethy1)-1 : 3 : 5-dioxazseptan is the effect of' dilute alcoholic potassium hydroxide on it, Under these conditions it was found to lose one molecule of hydrogen chloride very readily, giving rise t o a stable, saturated compound melting a t approximately the same temperature. Since, theoretically, chlorine in the form of hydrogen chloride could be eliminated from any one of the three trichloromethyl groups, the action of potassium hydroxide on the condensation product of chloralcyanohydrin and bromal hydrate (VII) was investigated. Under the same conditions, a similar coin- pound was obtained, the analysis of which proved it t o have the empirical formula C,,H,O,NCl,Br,, that is, hydrogen chloride, and not hydrogen bromide, had been eliminated. From this it follows by analogy that the chlorine in both cases must have been eliminated from the trichloromethyl group adjacent to the CO-group.

EXPERIMENTAL. 6-Keto-2 : 4 : 7-tri-(tric~lorometh?/I)-1 : 3 : 5-dioxazseptan (11).

Varying yields of this compound up to 30 per cent. were obtained by adding slowly 100 grams of powdered chloral hydrate t o 14 grams of powdered potassium cyanide in 200 C.C. of benzene; the containing vessel was shaken well and kept cool. After the mixture had been allowed to remain for three hours, the solution

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CONDENSATIONS OF CPANOHYDRINS. PART 11. 939

was filtered from the tarry matter produced, the benzene evaporated off in a draught a t room temperature, and the solid recrystallised from benzene.

A better method of preparation consisted in adding slowly, with repeated shaking, a saturated, aqueous solution containing 14 grams of potassium cyanide to a saturated, aqueous solution of 100 grams of chloral hydrate. After about half an hour the dioxazseptan derivative was precipitated as a white powder. The mixture was allowed to remain for about twelve hours; the solid was then separated, washed thoroughly with water, and recrystallised from benzene. The yield was 30-40 per cent. of the theoretical, and the substance melted and decomposed a t 1 2 3 O .

The same compound can be prepared also by adding slowly a 50 per cent. aqueous solution of potassium hydroxide t o a con- centrated, aqueous solution containing 1 2 grams of chloral hydrate and 6 grams of chloralcyanohydrin. When the product was re- crystallised from benzene the yield was 6 grams.

This compound is soluble in water, sparingly so in light petro- leum, moderately so in pyridine or toluene, readily so in methyl, ethyl, and amyl alcohol, and very easily soluble in glacial acetic acid or acetone. It can be recrystallised from benzene or ether, but, as it shows a very marked tendency to undergo decomposition when boiled in a solvent, it is inadvisable to recrystallise the sub- stance. For many of the experiments described here, the material used consisted of the crude product, which was washed thoroughly with water.

When the compound was heated above its melting point or was distilled in a vacuum it decomposed into ammonia, chloral, and chloralide. When the substance was heated in a sealed tube with water a t 180°, there resulted a mixture of acid products which yielded chloroform and ammonia on being warmed with potassium hydroxide.

The dioxazseptan derivative was heated f o r seven minutes with a mixture of hydrochloric acid and glacial acetic acid, and the mixture was cooled in ice, when crystals separated which, when recrystallised from ether, melted a t 114O. This was identified as chloralide. (Found, C1= 66.3. Calc., C1= 65.9 per cent.)

6-Keto-5-ethylcarbonato-2 : 4 : 7-tri-(trichloromethyl)-l : 3 : 5- dioxasseptan.

To 10 grams of 6-keto-2 : 4 : 7-tri-(trichloromethyl)-l : 3 : 5- dioxazseptan, dissolved in a mixture of pyridine and toluene, excess of ethyl chloroformate was added, and the flask cooled. A i h r the mixture had remained for eighteen hours it was poured into dilute

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940 CROWTHER, McCOMBIE, AND READE :

hydrochloric acid, the toluene layer separated, the aqueous portion extracted twice with toluene, and the united toluene solutions were evaporated to dryness in a draught a t room temperature. The solid, when crystallised from ethyl alcohol, separated in colourless prisms, which melted a t 152O.

0.1439 gave 0.3441 AgC1. C1= 59.2. C,oH80,NC1g requires C1= 59.0 per cent.

This compound was insoluble in water, sparingly soluble in methyl alcohol, readily so in benzene or light petroleum, and very easily so in chloroform or ether.

The yield was 8 grams:

6-Keto-5-acetyl-2 : 4 : 7-tri-(trichloromethyl)-l: 3 : 5-dioxasseptan.

This preparation was similar in detail to that of the ethyl- carbonato-derivative, acetyl chloride in a cold mixture of pyridine and toluene being employed. The substance, after three recrystal- lisations from methyl alcohol, separated in colourless, prismatic needles, forming radiating clusters, which melted a t 161O. The yield was 60 per cent. of the theoretical. Attempts to prepare this derivative by means of acetic anhydride and sodium acetate gave only traces of the compound:

0.1446 gave 0-3641 AgC1. C1=62*3. 0.3722 ,, 8.95 C.C. N, a t 16.5O and 748.5 mm. N=2.76.

C9H80,NC1, requires C1= 62.4 ; N = 2-74 per cent. This compound was insoluble in water, moderately soluble in

ethyl alcohol, readily so in benzene or ether, and very readily so in chloroform. It can be recrystallised from light petroleum or from methyl alcohol.

6-Keto-5-bensoyl-2 : 4 : 7-tm'-(trichloromethyl)-l : 3 : 5- dioxazseptan (VII) .

This compound is produced by the Schotten-Baumann reaction, but the yield is only about 5 per cent. of the theoretical. It was prepared in pyridine and toluene solution in a manner similar t o that described f o r the ethylcarbonato-derivative ; the yield was 70 per cent. of the theoretical. The substance, when recrystallised from absolute alcohol, separated in small, prismatic needles, which melted a t 142O:

0.1433 gave 0.3232 AgC1. C1=55-8. 0.4605 ,, 9.9 C.C. N, a t 18'5O and 738 mm. N=2.46.

This benzoyl derivative was insoluble in water, moderately soluble C,,H80,NC1, requires c1= 55.7 ; N = 2'45 per cent.

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CONDENSATION8 OF CYANOHPDRINS. PART 11. 941

in light petroleum, readily so in benzene, very readily soluble in ether or acetone, and extremely so in chloroform. When this com- pound was heated on a water-bath for two and a half-hours with alcoholic potassium hydroxide it yielded, on acidification, a con- siderable quantity of benzoic acid. It remained, however, entirely unchanged when heated in alcoholic solution with aqueous sodium carbonate.

When this benzoyl derivative was heated with hydrochloric acid in eithgr alcoholic or glacial acetic solution, the ring was opened, one of the chloral residues was eliminated, and the compound pro- duced was 13-trichloro-a-(Pf-trichloro-a’-hydroxyethoxy)-propiono- benzamide (IX).

When attempts were made to reduce the benzoyl derivative with hydrogen in the presence of colloidal palladium (Paal’s method) i t was found that hydrogen was absorbed slowly and steadily, but no product. except the usual degradation products could be isolated.

Hydrogen peroxide had no action whatever on the compound in acetic acid solution. The oxidation was then attempted by means of chromic acid in glacial acetic acid. A vigorous reaction took place, and the chromic acid was reduced. On isolating the product, by pouring the mixture into water, i t was found t o be identical with the one obtained by acid hydrolysis of the benzoyl derivative, and on treating with sodium carbonate solution, the same pyrrolidone derivative was obtained. The chromic acid simply oxidised away one of the chloral residues to trichloroacetic acid.

The effects of oxidation were next tried.

C,,H,O,NCI, + H,O + 0 -+ CCI,*CO,H + C,,H,0,NCJ6 (IX.)

(VII.)

Action of Potassium Hydroxide o n 6-Keto-5-bensoyl-2 ; 4 : 7-h-i- (trichloromethy1)-1 : 3 ; 5-dioxasseptan (VII).

Preparation of the Compound C,,H,O,NCl,.

This compound was obtained by adding very slowly about 1 gram of potassium hydroxide, dissolved in a small quantity of water and alcohol, to an alcoholic solution of the above benzoyl derivative (1 gram), which was heated on a water-bath. The solution gradu- ally became brown, and, after about half an hour, potassium chloride crystallised from the alcoholic solution. The mixture was then poured into dilute hydrochloric acid, and the solid which separated was crystallised from ethyl alcohol, when it was obtained in needles, melting a t 124-125O:

VOL. cv. 3 Q

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942 CROWTHER, McCOMBIE, AND READE :

0.2110 gave 0.4530 AgCl. C1=53*11. 0.1814 ,, 4-95 mgms. N,. N=2*73.

This compound was insoluble in dilute acids or alkalis. C,,H,O,NCl, requires C1= 52.89 ; N = 2-61 per cent.

It was decomposed by concentrated potassium hydroxide, with the forma- tion of benzoic acid. It dissolved in concentrated sulphuric acid, giving a pale green colour ; this coloration disappeared on warming the solution gently, and the compound was decomposed, with the formation of chloral and benzoic acid. It was stable towards bromine and permanganate. The substance appeared to be hydro- lysed by hydrochloric acid in glacial acetic acid, similarly to the original benzoyl derivative. The mixture was poured into water, and the precipitated solid, when washed free from benzoic acid, consisted of a fairly pure compound, which melted a t 112-113O:

0.0864 gave 0'1461 AgC1. C1=41.8. C,,H80,NC1, requires Cl = 43.6 per cent., whilst C,2H,,0,NCl,

requires C1= 41.7 per cent. Owing to the unstable nature of this compound, a pure specimen

could not be obtained by recrystallisation. The substance was extremely soluble in alcohol or acetone, and moderately so in light petroleum.

Many attempts were made to convert this substance into the pyrrolidone derivative (X), but all attempts proved unsuccessful, owing to the ease with which the compound suffered complete de- composition. It dissolved very readily in dilute sodium carbonate, and was completely decomposed, only benzoic acid being recovered when the solution was poured into acid. Dilute alkalis o r ammonium hydroxide decomposed it in a similar manner. No benzoyl derivative could be obtained, decomposition probably taking place.

P-Tric hloro-a-(P 1 -trichloro-a f-h ydroxy ethoxy)-propiono- b enzamide (IX).

This compound was obtained by heating 4 grams of the benzoyl derivative with a mixture of 20 c.C. of hydrochloric acid and 80 C.C.

of glacial acetic acid, and extracting the cold solution with chloro- form. A better method of preparation was found t o consist in heating 4 grams of the benzoyl derivative with a mixture of 10 C.C.

of hydrochloric acid and 90 C.C. of absolute alcohol on a water-bath for two hours. The solution was then evaporated to dryness in a draught a t room temperature or poured into water, and the result- ing solid crystallised from benzene, from which it separated as a white powder, melting a t 166O. I n spite The yield was 1.6 grams.

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CONDENSATIONS OF CYANOHPDRINS. PART 11. 943

of many recrystallisations, this substance could not be obtained pure, as it seemed to undergo partial decomposition :

0.1340 gave 0.2579 AgC1. 0.3598 ,, 9.95 C.C. N, a t 16.6O and 746 mm. N=3*16.

C,,HgO,NCl, requires C1= 47.9 ; N = 3.16 per cent. This compound was sparingly soluble in water or light petroleum,

readily so in et'hyl alcohol or ether, and very readily so in pyridine. It behaved as a saturated compound towards bromine, and was not altered when heated with hydrochloric acid for four hours.

When this compound was boiled with alcoholic potassium hydroxide or with sodium carbonate, a clear solution was obtained, which, on acidification with dilute acid, yFlded a mixture of benzoic acid and 4 : 4-dichloro-3 : 5-oxido-5-trichloromethyl-2-pyrrolidone

The ace tyl derivative, CH( CC1,) (OAc) *O*CH( CCI,) *CO*NHBz, was formed by warming the substance f o r three hours with acetic anhydride and a trace of acetyl chloride. A better method of pre- paration consisted in dissolving half a gram of the substance in a mixture of pyridine and toluene, cooling in ice, and adding acetyl chloride. After the mixture had been allowed to remain for eighteen hours, it was poured into dilute hydrochloric acid, the toluene portion being separated and evaporated to dryness in a draught a t room temperature. The resulting solid, after three re- crystallisations from a mixture of alcohol and water, melted a t 167O.

C1= 47.6."

(X).

The yield was 0.25 gram: 0.1761 gave 0.3114 AgCl. C1=43*8.

This derivative was insoluble in water, sparingly soluble in light petroleum, and readily so in benzene.

The b enzoyl derivative, CH(CC1,) (OBz) *O*CH ( CCl3).CO*NHBz, was prepared by the action of benzoyl chloride on the propiono- benzamide derivative (IX) dissolved in a mixture of dry acetone and pyridine. When the mixture had remained for a few hours it was poured into acid, and the solid which separated was crystal- lised from ethyl alcohol, when it melted a t 168-169O :

Cl4Hl1O,NC1, requires c1=43*8 per cent.

0.1951 gave -0.3042 AgC1. C1=38-57. C1gHl3O5NC1, requires C1= 38-87 per cent.

4 ; 4-Dichzoro-3 : ~ - o x ~ d o - ~ - t ~ ~ c h ~ o r o m e t h ~ ~ - ~ - ~ r r o ~ ~ ~ o n e (x). Two grams of 8-trichloro-a-(@-trichloro-a'-hydroxyeth0xy)-

propionobenzamide were heated under reflux with alcoholic

* Analyses of different specimens gave (31-46.3, 48.6.

3 Q 2

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944 CROWTHER, McCOMBIE, AND READE :

potassium hydroxide on a water-bath for eight minutes, and the mixture was poured into water, when a clear solution resulted. No odour of ammonia or of chloroform could be detected. The solu- tion was acidified with nitric acid, and the solid, after being washed with water, was crystallised from light petroleum or dilute alcohol, when it was found to melt a t 209O. The yield was 0.4 gram:

0.1491 gave 0.3741 AgCl. C1=62*1. 0.2182 ,, 9.1 C.C. N2 a t 13-8O and 752.2 mm. N=4*86. 0.2012 ,, 103.2 C.C. CO,+N, a t 14'3O and 672.4 mm., which

gave 8.0 C.C. N, a t 1l0 and 765 mm. C=20*85; N=4*78. C,H,O,NCl, requires C1= 62.1 ; N = 4-91 ; C = 21.1 per cent.

This substance was very sparingly soluble in water, and readily so in alcohol, benzene, o r chloroform. It was readily soluble in excess of dilute ammonium hydroxide, sodium carbonate, or sodium hydroxide, and on the addition of acids to these solutions i t was recovered unchanged. The compound was stable towards bromine and towards potassium permanganate, but on boiling with concen- trated potassium hydroxide it was decomposed, with evolution of ammonia. By means of a solution of hydrobromic acid in glacial acetic acid, attempts were made to open the ring, but the com- pound was recovered unchanged. On treating the substance with methyl sulphate, a methyl derivative was obtained.

The methyl derivative, C613[,02NC1,, was prepared by heating the compound with methyl sulphate in the presence of sodium hydroxide. Excess of methyl sulphate was destroyed, and the white solid which separated was crystallised from dilute alcohol, when it was obtained in silky needles, melting a t 119O. Other methods of alkylation were tried, f o r example, treating the sodium salt with alkyl iodides, but these proved unsuccessful :

0.1183 gave 0'2832 AgC1. C1=59*23. C6H402NC1, requires C1= 59.26 per cent.

This methyl derivative was readily soluble in all the usual organic solvents, but, unlike the parent substance, it possessed no acid properties. It was decomposed completely by concentrated potassium hydroxide.

6-Keto-7-trichloromethyl-2 : 4-&(tribromomethyl)-l : 3 : 5- dioxasseptan (V).

This compound was prepared by adding very slowly, a t room temperature, a concentrated solution of potassium hydroxide to a concentrated solution of chloralcyanohydrin (7 grams) and bromal hydrate (24 grams). A precipitate was produced, which was

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CONDENSATIONS O F CYANOHYDRINS. PART 11. 945

washed thoroughly with water and dried. Attempts t o crystallise this compound were unsuccessful, because it was found to decom- pose rapidly in hot organic solvents. The yield wag 12 grams, and the product melted a t 132O:

0.1424 gave 0*3002 AgCl+ AgBr.

This substance was insoluble in water, somewhat soluble in cold toluene, and readily so in pyridine. On treatment with acetyl chloride or benzoyl chloride it yielded an acetgl or a benzoyl derivative respectively.

When 1 gram of this substance was boiled for seven minutes with 80 C.C. of glacial acetic acid and 20 C.C. of hydrochloric acid, and the flask cooled in ice, crystals separated out, which melted a t 149O. These were recrystallised with difficulty from absolute ether, and were identified, by analysis and properties, as the tribroino- ethylidene ester of trichlorolactic acid. (Found, 0.0913 gave 0.1977 AgCl+ AgBr. Calc., 0.1988.) This compound was described previously by Wallach (Annalen, 1878, 193, 53).

C7H,0,NC13Br6 requires AgCl + AgBr = 0.3012.

6-Ke tod-ace t yl-7-tric hlorome t h yl-2 : 4-di-(tri bromom e t hy1)- 1 : 3 : 5-dioxazseptan.

This preparation was similar to that of the acetyl derivative of the corresponding chloral compound. The solid was crystallised from ethyl alcohol, in which it is fairly soluble, and melts and decomposes a t 158O. The yield was 50-60 per cent. of the theoretical :

0.1286 gave 0.2590 AgCl+ AgBr.

This compound was insoluble in water, moderately soluble ill C,H,O,NCl3Br6 requires AgCl + AgBr =0-2574.

benzene or ether, and readily so in chloroform.

6-Keto,5-b enzoyl-7-trichloromet hyl-2 : 4-di-(tribromometh yl)- 1 : 3 : 5-dioxaeseptan.

This compound was prepared by the action of benzoyl chloride in When recrystallised from ethyl

The a mixture of pyridine and toluene. alcohol, in which it is sparingly soluble, i t melted a t 163O. yield was 60 per cent. of the theoretical:

0.1381 gave 0.2551 AgCl+ AgBr. 0.7174 ,, 10'2 C.C. N, a t 11.8O and 737.5 mm. N=1'64.

C,H,04NC1,Br6 requires AgCl + AgBr = 0.2559 ; N = 1-63 per cent. This benzoyl derivative was insoluble in water, sparingly soluble

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946 CONDENSATIONS OF CYAKOHYDRINS. PART 11.

in hot ethyl alcohol, moderately so in ethyl acetate, and readily so in chloroform, ether, or acetone.

4 ; 4-Dichloro-3 : 5-oxidod-tribromomethyL2-pyrrolidone (XI), C,H,O,NC~Br,.

This preparation was similar to that of the corresponding trichloromethyl derivative (X). The 2-keto-5-benzoyl-7-trichloro- methyl-2 : 4-di-(tribromomethyl)-l: 3 : 5-dioxazseptan was hydro- lysed by means of a 10 per cent. alcoholic solution of hydrogen chloride on a water-bath for several hours. The mixture was then poured into water, and the product, which separated after some time, was washed with water. Like the corresponding trichloro- derivative, it was unstable, and no attempt was made a t further purification. The substance was then boiled for about a minute with a solution of sodium carbonate, when most of it dissolved, any solid remaining being removed by filtration. The solution was acidified, and the white solid which separated was washed with hot water to free it from benzoic acid, and was recrystallised two or three times from dilute alcohol or from light petroleum, when it melted and decomposed a t 225O. The yields throughout were very poor. An estimation of both chlorine and bromine was obtained by converting the mixed haloids into silver chloride by passing a stream of chlorine through the crucible containing the haloids, which were heated just to the point of fusion:

0.0722 gave 0.1468 AgCl+ AgBr, which gave 0.1237 AgCl after conversion. C,H2O2C4Br3 requires C1= 16.95 ; Br =57% per cent.

C1= 16.82 ; Br = 57-52.

Action of Dilute Alcoholic Potassium Hydroxide on 2-Reto-5- b enzoyZ-7-trichloromethyl-2 : 4-di-(tribromomethyt)-1: 3 ; 5- dioxazseptan.

Preparation of the Compound C,,H,O,NC~Br,.

,CH*CO-N Bz /CH* COON BZ /

I o< / I CCI, I o< ‘-CClq I or

\C-O--CH*C I Rr, \CH--0-C*CBr, I

d ~ r , CBr, This compound was obtained by adding slowly an alcoholic solu-

t ion of potassium hydroxide to the benzoyl derivative dissolved in ethyl alcohol, and heated on a water-bath (compare the preparation of the compound C,,H,O,NCl,). The mixture was poured into dilute acid, and the solid which separated was crystallised from

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THE CONNEXION BETWEEN THE DIELECTRIC CONSTANT, ETC. 947 ethyl alcohol, in which it was only sparingly soluble. fine needles, which melted at 163O:

0.0842 gave 0.1468 AgCl+ AgBr.

It formed

C,,H70,NC12Br, requires AgCl + AgBr = 0.1480. CHEMICAL DEPARTMENT,

THE UNIVERSITY, EDGRASTON, BIRMISGHAM.

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