Unusual Structure and Reactions of l-Phenlpyrazol-5-one Annulated with 1-Methylpiperidine. A Rare Case of Auto-Alkylation

摘要

The interaction of l-alkyl-3-alkoxycarbonylpyperidin-4-ones with phenylhydrazine has led to 5-alkyl-2-phenyl-3,3a,4,5,6,7-hexahydro-2//-pyrazolo-[4,3-c]pyridin-3-ones. The prepared compounds are unstable and undergo a series of uncommon transformations; their mechanisms have been suggested basing on the structural analysis of the product mixtures.