The orientation of the COOC2H5‐group in the condensation product of malonic ester and β‐aminocrotonic acid ester

A proof is given that in the condensation product formed by the interaction of malonic ester and β-aminocrotonic acid ester, namely 2-methyl-4,6-dihydroxypyridine-carboxylic acid ester, the COOC2H5-group occupies the 5-position. This was effected by exchanging the hydroxyl groups for chlorine atoms and subsequently replacing these atoms by hydrogen atoms. The structure of the resulting 2-methylpyridine-carboxylic acid ester was established by conversion into the corresponding picrate, carboxylic acid and amide. The identities of these compounds with 2-methylpyridine-5-carboxylic acid ester-picrate, 2-methylpyridine-5-carboxylic acid and -amide were proved by mixed melting points with samples of these substances prepared from 2-methyl-5-ethyl-pyridine.