OF ARTS AND SCIENCES. 236 



XI. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OP 

 HARVARD COLLEGE* 



ON THE DIIODBROMACRYLIC AND CHLORBROM- 

 ACRYLIC ACIDS. 



By C. F. Mabery and Rachel Lloyd, 



Presented by H. B. Bihh. 



The readiness with which brompropiolic acid unites with the halo 

 gens and the haloid acids to form members of the acrylic acid series 

 has been described by Prof. H. B. Hill,t and certain of these addition 

 products have been studied in detail by him and one of us. J 



The products which result by the action of iodine and of hydro- 

 chloric acid on brompropiolic acid will be described in this paper. 



Diiodbromacrtlic Acid, CnlgBrO^H. 



Diiodbromacrylic acid is formed when brompropiolic acid is allowed 

 to stand for some time with a solution of iodine in ether. As this method 

 of preparation was found to be somewhat tedious from the length of 

 time required to complete the reaction, we tried the effect of raising 

 the temperature. Brompropiolic acid, with a slight excess over the 

 calculated weight of iodine and five parts by weight of ether, was 

 heated for two hours under a return condenser on the water bath. 

 The residue left after the evaporation of the ether was extracted with 

 successive portions of warm water, and the solution concentrated by 

 evaporation/ Diiodbromacrylic acid was deposited from this solution, 

 on cooling, in glistening plates, which were purified by recrystalliza- 

 tion from hot water. 



* This research was conducted in connection with the Summer Course of 

 Instruction in Chemistry. C. F. M. 



t Berichte der deutsch. chem. Gesellscli., 1879, p 660. 

 t These Proceedings, p. 211. 



