OF ARTS AND SCIENCES. 277 



XIX. 



CONTRIBUTIONS FROM THE CHEMICAL LABORATORY OF 

 HARVARD COLLEGE. 



THE (3 PHENYLTRIBROMPROPIONIC ACID. 

 By Leonard P. Kinnicutt and George M. Palmer. 



Presented May 9th, 1883. 



The a phenyltribroinpropionic acid and the products formed when this 

 acid is decomposed by boiling water were briefly described by one of 

 us last year.* During the past winter the study of the /3 acid was 

 undertaken, and it has been considered best to give at this time the 

 results so far obtained, as the further investigation must be carried on 

 in different relations. 



The f3 phenyltribrompropionic acid was obtained by the notion of 

 dry bromine on /3 monobromcinnamic acid, this last having been pre- 

 pared in the way previously described. t 



By the action of bromine on j3 monobromcinnamic acid, GlaserJ 

 obtained an acid, which he describes as melting during the absorption 

 of the bromine and only solidifying again after several days. The 

 melting point he found to be 45-48° C. The results obtained by us 

 are very different. Perfectly pure /3 monobromcinnamic acid melting 

 at 120° C. was placed under a bell glass with the theoretical amount of 

 bromine. Not the slightest indication of melting was observed, and 

 after twenty-four hours the bromine was all absorbed. The acid so 

 obtained was purified by crystallization from chloroform and melted 

 at 151° C. It is soluble in alcohol, ether, carbonic disulphide, chloro- 

 form, and benzol. 



The analyses gave the following results: — 



1. 0.2711 gr. substance gave 0.2788 gr. CO, and 0.0454 gr. H.p. 



2. 0.3845 gr, substance gave 0.3912 gr. CO2 and 0.0702 gr. Rfl. 



3. 0.1894 gr. substance gave 9.2769 gr. AgBr. 



4. 0.1839 gr. substance gave 0.2696 gr. AgBr. 



* Kinnicutt, Amer. Chem. Jour., iii. 4. t Ibid. 



} Annalen der Chemie, cxliii. 339. 



