Benzimidazol‐Derivate und verwandte Heterocyclen. IV. Die Kondensation von o‐Phenylendiamin mit α‐Aryl‐ und γ‐Aryl‐acetessigester

The reaction of o‐phenylenediamine with α‐phenyl‐ and γ‐phenyl‐acetoacetic ester has been investigated. The former yields mainly 1‐β‐methylstyryl‐benzimidazole‐2‐one (IX), the latter affords 4,7‐dihydro‐5‐benzyl‐1 H ‐2,3‐benzo‐1,4‐diazepin‐7‐one (XVI). The structures of these products have been elucidated.