The Nucleophilic Displacement Reactions of 8-Chloro- and 2,8-Dichloro-3-phenyl-1-azaazulenes

Abstract

Abstract The reaction of 3-phenylpyrrolo[2,3-b]tropone (7) with phosphoryl chloride gave 8-chloro-3-phenyl-1-azaazulene (5). When 5 and 7 were treated with N-chlorosuccinimide, 2,8-dichloro-3-phenyl-1-azaazulene (6) and 2-chloro-3-phenylpyrrolo[2,3-b]tropone (8) were obtained respectively. 6 was also obtained from 8 by treatment with phosphoryl chloride. The reactions of 5 and 6 with nucleophilic reagents gave the corresponding substituted products (14a–m and 15a–m). 8-Hydrazino-3-phenyl-1-azaazulene (14m) and 2-chloro-8-hydrazino-3-phenyl-1-azaazulene (10), which had been obtained by the reaction of 5 and 6 with hydrazine hydrate, were decomposed by treatment with copper(II) sulfate in acetic acid to give 3-phenyl-1 -azaazulene (2) and 2-chloro-3-phenyl-1-azaazulene (11) respectively.