ACETO ACETIC ESTER II5 



of comparisons of the three isomeric bodies Cs Hg O4 . They are 

 assigned the following formulae. For dehydracetic : — 



CH3C— O- c=o 



CH-CO— CHCOCH3 

 or the tautomeric forms of: — 



CH3-C— O— C=0 CH3— C— O — C:0 



CHC (OH) : CCOCH3 or :— CHCO— CC (OH) CH3 . 



For a — a-dimethyl-pyron-carboxylic acid : — 



CH3C— O— CCH3 



II II 



CHCO— C— CO2H 



and for isodehydracetic acid : — 



CH3C O C:0 



CHC(CH3) :CCO,H. 



PETERS, THEODOR, 1890. 



Ann. Chem. 257, 339-353 ; J. Chem. Soc. 58, 1097 ; Ber. 23, 468 (C). 

 Action of Alkyl Substituted Acetoacetic Esters with Ammonia. 



By the action of ammonia on these esters two products are formed 

 (i) a-alkyl-/9-amido-crotonic acid, CH3 C (NH^) : CRCO2 R, and (2) 

 amids of alkylacetoacetic acid, CH3 COCHRCONH2 , but the former 

 only is produced when anhydrous ammonia is employed. Ethyl- 

 acetoacetic methyl ester yields ethyl-amido-crotonic methyl ester, 

 CH3 C (NH,) : C (C2 H5) CO. CH3 , which melts at 35°-36°, and ethyl- 

 acetoacetamid, CH3 COCH (C2 H5) CONH. , melting at 96° Methyl- 

 acetoacetic ester yields methyl-acetoacetamid, CH3COCH(CH3)CONH2, 

 melting at 73° a-Methyl-/5-amido-crotonic ester melts at 53° Isobutyl 

 acetoacetamid melts at 88°, a-isobut}4-;?-amido-crotonic ester melts 

 at 41° -42°, isoamyl-acetoacetamid, CH3 COCH (C5 Hu) CONH2 , melts 

 at 129° and a-isoamyl-/3-amido-crotonic ester, CH3 C (NH2) : C (C5 Hu) 

 CO2 C2 H5 , melts at 50.° Diethyl-acetoacetic ester is not attacked by 

 either anhydrous or aqueous ammonia. 



