216 PROCEEDINGS OP THE AMERICAN ACADEMY 



calculated amount. The substance as thus obtained was found to 

 be identical in composition and physical properties with that 

 formed by the action of bromine and dilute potassium hydroxide 

 on the dibromamide. A combustion of this product gave the 

 following results : — 



0.4272 grm. substance gave 0.3793 grm. C0 2 and 0.0217 grm. 

 H 2 0. 



Calculated for C 5 HBr 2 NO. Found. 



C 23.90 24.21 



H 0.40 0.56 



Properties of fiS-Dibromfitrfuronitrile. — It is a colorless solid, 

 possessing a characteristic and rather pleasant odor. It is volatile 

 with steam, scarcely at all soluble in water, readily soluble in ether 

 and in hot alcohol (especially at 100° under pressure). Its melting 

 point is 88° (uncor.), and its boiling point 225° (uncor.). It can 

 be sublimed. It crystallizes from superheated alcohol in leaflets or 

 plates. On standing for several days in a warm room with concen- 

 trated hydrochloric acid, it is converted into /?S-dibrompyromuca- 

 mide. When it is heated for about an hour in a sealed tube at 

 100° with concentrated hydrochloric acid, a considerable amount 

 of /38-dibrompyromucic acid is formed. Prolonged heating causes 

 blackening. 



These two reactions were tried with the nitrile prepared in both 

 ways. In alcoholic solution sodium amalgam formed no reduction 

 product. The nitrile was dissolved in dilute alcohol, and treated 

 with two per cent sodium amalgam, a current of carbon dioxide 

 being passed through until the action was over. The distillate 

 obtained from this was not alkaline, and gave practically no resi- 

 due when acidified and evaporated. The residue in the flask gave, 

 on evaporation, needles of /38-dibrompyromucamide. 



When the solution of dibromamide in bromine was treated with 

 dilute cold potassium or sodium hydroxide, the only product found, 

 beside the nitrile, was monobrommaleic acid. This was identified 

 by its melting point and other physical properties, as well as those 

 of its barium salt. 



The dehydration of the dibromamide, — under the conditions of 

 the experiments related, — with formation of the nitrile, is par- 

 ticularly interesting, because Hofmann * found that, in preparing 



* Berichte der deutsch. chem. Gesellsch., XVII. 1406, 1920. 



