ACETO ACETIC ESTER I}! 



but probably is the latter. The same substance can be formed from 

 uramidocrotonic ester and benzaldehyde. It is very stable as it is not 

 affected by strong acids or alkalis in the cold. Heating it with 

 potassium hydroxid gives benzyl alcohol, benzaldehyde, ammonia and 

 potassium carbonate, besides an unknown solid substance. Salicj^al- 

 dehyde, cinnamaldehyde, furfuraldehyde, cumaldehyde and others 

 react similarly. 



BEYER, C, 1891. 



Ber 24, 1662-1670; J. Chem. Soc. 60, 1090. 



Hantzsch's Pyridin Synthesis, 



The author believes that in these reactions acetoacetic ester and 

 aldehyde first react to form ethylidin-acetoacetic ester, 



CH3 



I 



CH, 



CO2 RC 



CH3 CO 



and that this then unites with acetoacetic ester to form ethylidin- 



diacetoacetic ester, 



CH3 



I 

 CH 



/ \ 

 CO2 RC CHCO2 R 

 H| I 

 CH3 COOCCH3 



which unites with ammonia to form dihydrocollidin-dicarboxylic ester, 



CH3 



CH 



/\ 

 CO2R. C CCO2R. 



II II 

 CH3C C-CH3 



\/ 

 N 



I 

 H 



