130 PROCEEDINGS OF THE AMERICAN ACADEMY 



Calculated for KC8HBr202 Found. 



I. II. 



K 14.58 14.53 14.51 



Although many unsuccessful attempts had previously been made to 

 prepare brompropiolic acid in a pure state, it seemed to me not im- 

 possible that the prolonged action of alkalies in the cold might remove 

 from the dibromacrylic acid a molecule of hydrobromic acid, and that 

 a purer product might thus be obtained. I found, however, that the 

 reaction was extremely slow, at least with baric hydrate. An aqueous 

 solution which contained one molecule of baric hydrate to each mole- 

 cule of dibromacrylic acid was strongly alkaline even after standing 

 for fifteen days, and gave on acidification and extraction with ether 

 the compound of brompropiolic and dibromacrylic acids which has 

 already been described. After recrystallization from ligroin the sub- 

 stance melted at 103°, and gave on analysis the following result : — 



0.2535 grm. substance gave 0.3766 grm. AgBr. 



Calculated for CeHaBfaOi . Found. 



Br. 63.33 63.22 



Since I had before noticed that this intermediate product could be 

 obtained from dibromacrylic acid by the action of baric hydrate in the 

 course of a few hours, and that malonic acid was formed even in the 

 cold after the lapse of several months, it was evident that further 

 attempts in this direction were useless. 



