118 W. A. Drushel — Preparation and Hydrolysis of 



In another experiment 26 - 4 grms. of hydracrylic acid were 

 gently boiled with 200 cm3 of absolute alcohol in the presence of 

 about 50 grins, of anhydrous copper sulphate freed from sul- 

 phuric acid, by means of absolute alcohol. At the end of three 

 hours 66 per cent of the acid was esterified, at the end of six 

 hours 71*4 per cent ; at the end of nine hours 83 per cent of 

 the theoretical amount of ester was formed and the boiling 

 was discontinued. To remove the unesterified hydracrylic 

 acid in this and in the previous experiment a little less than 

 the theoretical amount of anhydrous sodium carbonate was 

 added to the esterification mixture and the excess of alcohol 

 was distilled off on the water bath. The hydracrylic ester was 

 extracted from the residue with dry ether and the ether dis- 

 tilled off on a warm water bath, finally heating the water bath 

 to boiling. From the two experiments 53 grms. of crude 

 hydracrylic ester were obtained which on fractionation under 

 diminished pressure yielded 45 grms. of ethyl hydracrylate boil- 

 ing at 95-5°* to 96° at a pressure of 20 mm to 22 mm . The saponi- 

 fication equivalent of the ester so prepared was found to be 

 119, and the saponification equivalent calculated from the 

 formula CH 2 OH.CH 2 .COOC 2 H 5 is 118. When the ester was 

 dissolved in an equal volume of water and was treated with 

 phosphorus and iodine both beta-iodopropionic acid and beta- 

 iodopropionic ester were obtained. The ester at 20° has a 

 density of 1*059, and like lactic ester is soluble in water in all 

 proportions. These properties were considered sufficient to 

 identify the ester as pure ethyl hydracrylate. The ester has a 

 faint ethereal odor, much less pronounced than that of lactic 

 ester. It is unusually stable in water solution, hydrolyzing 

 very slowly in the absence of a catalyzing acid or alkali. 



Hydrolysis of the Ester. — Two and a half cubic centimeters 

 of ethyl hydracrylate were dissolved in 250 cm3 of decinormal 

 hydrochloric acid and hydrolyzed at 25°, 35° and 45°. The 

 course of the reaction was followed by titrating 25 cm3 portions of 

 the mixture at intervals as fully described in previous papers.* 

 The results of the velocity measurements are recorded in Table 

 I. In Table II are recorded summary results obtained partly 

 simultaneously with the reaction velocity measurements of 

 ethyl hydracrylate and taken partly from the results obtained 

 by Dean.f A striking contrast appears between the effects 

 of alpha hydroxyl and beta hydroxyl on the velocity of hydrol- 

 ysis of the esters in acid solution. This retarding effect of 

 the beta hydroxyl on the hydrolysis velocity of the ester was 

 predicted by Dean;}; for ethyl hydracrylate from his study of 



* This Journal, xxxv, 486, 1913. 



f Dean, this Journal, xxxv, 486, 1913. 



\ Dean, ]oc. cit. 



