Trichloroethyl alcohol

The undermentioned reductions may be carried out by simple adaptations to the procedures chloral to trichloroethyl alcohol m-nitroacetophenono of a-methyl-3-nitrobenzyl alcohol and o-nitrobenzaldehyde to o-nitroben l alcohol. 

By means of this reduction process it is possible to obtain, from the corresponding aldehydes, alcohols such as trichloroethyl alcohol or cinnamyl alcohol, which are not otherwise readily accessible or are otherwise inaccessible. Tnbromoethyl alcohol ( avertin ), an important narcotic, is prepared in this way (F. F. Nord). It is given by the rectum. 

The possibility of hydrogenating halogenated aldehydes and ketones by means of phytochemical reduction was tested as early as 1913 the successful results in this field clearly demonstrate the importance of this method. Lintner and Ltters found that chloral hydrate can be converted to trichloroethyl alcohol. This transformation takes place so easily that, according to Willstatter and Duisberg, it can be used under favorable experimental conditions as a convenient method for the preparation of the halogenated alcohol. The tribromoethyl alcohol may be prepared in an analogous manner. 

The mixture is then subjected to steam distillation until no more trichloroethyl alcohol passes over. About 4 1. of distillate is obtained (Note 6). The oil is separated from the aqueous layer and the latter is salted out by saturating with sodium sulfate and extracted with three 200-cc. portions of ether. The ether solution is added to the main portion of the alcohol and the whole is dried over anhydrous sodium sulfate. 

The ether is removed by distillation and the product distilled under reduced pressure (Note 7). There is obtained 215 g. (84 per cent of the theoretical amount) of trichloroethyl alcohol boiling at 94—97°/125 mm. and melting at 16-17° (Note 8). A purer compound can be obtained by refractionation under reduced pressure and pressing out the crystals on a cooled porous plate. Pure trichloroethyl alcohol has a melting point of 190 (Note 9). 

The method given here is essentially that of Meerwein and his pupils Schmidt5 and von Bock.3 The theory of the reaction and applications are also discussed by Dworzack 4 and by Ver-ley.6 A number of patents have appeared covering this reaction, in some of which a secondary alcohol such as isopropyl alcohol 7 is used in place of ethyl alcohol. Trichloroethyl alcohol is one of the chlorination products of alcohol and is found in the high-boiling fractions in the production of chloral.8 It was prepared by Garzarolli-Thurnlackh 9 and by Delacre10 by the action of diethylzinc on chloral. 

Trichloroacetic acid, 441, 1005, 1039, 1040, 1041 Trichlorobenzoic acid, 85 Trichlorobischlorophenylethane, 534 Trichlorobismethoxyphenylethane, 759 Trichlorobutanediol, 420 Trichlorobutylidene glycol, 420 Trichlorocarbanilide, 1041 Trichlorochlorophenylchlorophenylethane, 534 Trichloroethane, 1039 Trichloroethanediol, 441 Trichloroethanol, 1040 (metabolite), 441, 530, 1040,1041 quantification, 18 Trichloroethyl alcohol, 1040... 

The reaction is most useful for the preparation of olefinic, halo, and nitro alcohols from the corresponding substituted aldehydes and ketones. These substituents ate very often affected by other reduction procedures. Excellent directions are found in the preparations of crotyl alcohol (60%), l-bromo-5-hexanol (64%), l-chloco-4-pentanol (76%), /S,/S,/S-trichloroethyl alcohol (84%), methyl-p-chlorophenylcarbinol (81%), and o-nitrobenzyl alcohol (90%). The reaction has also been used in the preparation of certain tetralols and decalols as well as 9-fluo-renylcarbinol (50%). The thiophene and furan nuclei are not reduced. 

Tribromoethyl alcohol, avertin, is excreted as tribromoethyl glucuronoside (m.p. 145.5 [ajo —79.09 ) which has been isolated from the urine of rabbits after ingestion of the alcohol (95). Trichloroethyl alcohol appears to be excreted partly unchanged and partly as trichloroethyl glucuronoside (urochloralic acid) (216). 

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