α-OBSCURINE AND β-OBSCURINE: STRUCTURE STUDIES

Abstract

The alkaloid hitherto described as obscurine has been shown to consist of a mixture of two bases, α-obscurine (C₁₇H₂₆ON₂) and β-obscurine (C₁₇H₂₄ON₂). Dehydregenation of α-obscurine by heating with palladium-charcoal gives rise to 7-methylquinoline and 6-methyl-α-pyridone. The infrared absorption spectrum of the base shows absorption bands indicative of a carbony and of a secondary amino group, possibly in a cyclic lactam, while absorption in the ultraviolet indicates the presence of a double bond conjugated with the carbonyl group. β-Obscurine on the other hand contains an α-pyridone ring as shown by its infrared absorption spectrum and also by the similarity of its ultraviolet absorption spectrum with that of 6-methyl-α-pyridone.