514 W. A. Drushel — Substituted Aliphatic Acids. 



Art. XLII. — On the Hydrolysis of Esters of Substituted 

 Aliphatic Acids ; by W. A. Drushel. 



[Contributions from the Kent Chemical Laboratory of Yale University — cclviij 



8. Homologues of Ethyl Cyanacetate. 



From a study of the hydrolysis of ethyl cyanacetate* in 

 dilute hydrochloric acid solution the reaction velocity was 

 found to be lower than for the esters of the corresponding 

 halogen substituted fatty acids. In view of this marked retard- 

 ing effect in the ester hydrolysis apparently due to the presence 

 of the cyanogen group, it seemed desirable to determine the 

 rates of hydrolysis of other cyanogen substituted fatty acid 

 esters in dilute acid solution. For this purpose the following 

 esters were chosen : 



Ethyl a-cyanpropionate CH 3 CH(CN)COOC 2 H s , 

 ethyl /8-cy an propionate CH 2 (CN)CH 9 COOC 2 H 6 , 

 ethyl a-cyanbutyrate CH 3 CH 2 CH(CN)COOC 2 H 6 , 

 ethyl /3-cyanbutyrate CH„CH(CN)CH 2 COOC 2 H 6 , 

 ethyl a-cyanvalerianate CH 3 CH 2 CH 2 CH(CN)COOC 2 H 6 , 

 ethyl a-cyanisovalerianate (CH 3 ) 2 CHCH(CN)COOC 2 H 6 , and 

 ethyl a-cyandiethylacetate (C 2 H B ) 2 C(CN)COOC 2 H B . 



The ethyl esters of di-n-propylcj 7 anacetic acid and di-isopropyl- 

 cyanacetic acid were also prepared, but were found to be too 

 insoluble in dilute acid to be of use in this work. For the pur- 

 pose of comparison the ethyl esters of unsubstituted isovaleric 

 acid, caproic acid and diethyl acetic acid were prepared and 

 hydrolyzed. 



Preparation of Esters. 



(a) a-Cyan substituted fatty acid esters. — The previously 

 named a-cyan esters were prepared by the method described 

 by Henry,f and the monoalkylated esters were separated from 

 the corresponding dialkylated esters by the method of Hesslei*4 

 A concentrated alcoholic solution of sodium ethylate was 

 mixed with one equivalent of cyanacetic ester dissolved in 

 an equal volume of absolute alcohol. Reaction took place 

 immediately with the formation of the sodium salt of cyan- 

 acetic ester. Without separating the sodium salt it was treated 

 in the flask with an excess of alkyl iodide added through a 

 reflux condenser in small portions. The reaction was energetic 

 and within 30 minutes the reaction mixture, consisting 



* This Journal, xxxiii, 27. 



f Henry, Jahresber, 1889, 637. 



JHessler, Amer. Chem. Journal, xxii, 169; ibid., xxxv, 990. 



