Abstract Reactions of ethyl cinnamates with arylacetamides gave the corresponding 2, 6- diketo-3, 4-diarylpiperidine (1a-o) in addition to the corresponding cinnamides (2a-o) and arylacetates (3a-o). The latter two are formed from the intermediates of the Claisen condensation of the reactants. On the other hand and contrary to the above results, condensation of p-methoxycinnamate with arylacetamides gave only p-methoxycinnamide ...
