Ring contraction of 1,2,4-triazepino[2,3-a]benzimidazol-4-ones. New fused .beta.-lactams
摘要:
Isolation of uncommon fused tetracyclic beta-lactams 2 strongly supports a previously unconfirmed ionic mechanism for the ring contraction of nitrogen-bridged azolo-1,2,4-triazepin-3-ones in acetic anhydride. Procedures for the synthesis in good yields of substituted-pyrazolo[1,5-alpha]benzimidazoles from the corresponding [1,2,4]triazepino[2,3-alpha]benzimidazoles are reported.
Reactions of 1,2-diaminobenzimidazoles with β-dicarbonyl compounds
作者:C. Romano、E. De La Cuesta、C. Avendano、F. Florencio、J. Sainz-Aparicio
DOI:10.1016/s0040-4020(01)86088-9
日期:1988.1
The reactions of 1,2-diaminobenzimidazoles with β-dicarbonyl compounds give 1,2,4-triazepino [2,3-a]benzimidazole and pyrimido [1,2-a]benzimidazole-derivatives.