Studies on Quinolizine Derivatives. XV. Synthesis of Azacycl[3, 3, 3]azine Derivatives (8)

Abstract

From the reaction of 4-imino-6-methyl-4H-quinolizine derivatives (I) with acid anhydrides (glutaric anhydride and crotonic anhydride), the corresponding 1-azacycl-[3, 3, 3]azine derivatives (V, VI) were obtained. 1-Aza-5-oxo-2, 3, 4, 5-tetrahydrobenzo[b]cycl[3, 3, 3]azine (X) was yielded, as a stable free base, by the decarboxylation of VI. On the other hand, 2-methyl and 2, 5-dimethyl-1-azacycl[3, 3, 3]azine (XVIa, b), which were very unstable free bases, were prepared by the degradation of II and IV. These nuclear magnetic resonance spectral data of XVIa and XVIb may be interpreted in term of a paramagnetic ring current.