HILL AND CORNELISON. — CROTONOLACTONES. 13 



and obtained only the opianic oxime anhydride. We have been able 

 to find described no other experiments with the esters of the acids 

 in question. Our own experiments with mucobromic acid, and its 

 methyl ester, showed that the ester was attacked with much more 

 difficulty. While mucobromic acid is rapidly converted into its oxime 

 and oxime anhydride, we failed to discover any appreciable action 

 when hydroxylamine is added to a solution of methyl mucobromate in 

 methyl alcohol at ordinary temperatures even after the lapse of several 

 days. On boiling, the methyl ester of mucobromoxime was formed, 

 identical with the body formed by heating mucobromoxime with methyl 

 alcohol. Further experiments in this direction can alone show whether 

 the difference in behavior between the acids of this series and their 

 esters is sufficiently general to warrant definite conclusions as to their 

 structure. The action of phenylhydraziue upon mucobromic and 

 mucochloric acids and their esters, which we hoped to study in detail, 

 proved to yield bodies which were not suitable for investigation. 



Many years ago Mr. C. W. Andrews, who was at that time an 

 assistant in this Laboratory, made some experiments as to the action 

 of aniline upon mucobromic acid and its ethyl ester, which he was 

 unable to complete at the time, and which have never been published. 

 He found that the reaction with mucobromic acid was complex, in that 

 bromine was partially replaced by the aniline residue, and also that 

 oxygen was eliminated by condensation. In marked contrast with 

 this reaction was the behavior of ethyl mucobromate with aniline. 

 One atom of bromine was here replaced, but the rest of the molecule 

 remained unaltered, so that the body C 4 H 2 Br(NHC 6 H5)0 3 C2H5 

 was formed in nearly theoretical quantity. It therefore seemed to us 

 of interest to determine whether ethyl mucobromate would behave 

 in an analogous way with ammonia. We found, however, in this 

 case, that the reaction took a different course, and that the ethoxy 

 group was first attacked. The body which is thus formed has the 

 formula of the amide of mucobromic acid, but its behavior is in some 

 respects anomalous. It dissolves readily in caustic alkalies, and may 

 be reprecipitated unchanged by immediate acidification. It is but 

 slowly converted into mucobromic acid by boiling with mineral acids, 

 and with oxidizing agents it yields dibrommaleinimide. From muco- 

 chloric acid a body of similar properties was obtained. 



o/3-DlBROMCROTONOLACTONE. 



Although tribrompyromucic acid is little affected by boiling hydro- 

 chloric acid, it is quite readily decomposed, with the escape of carbonic 



