Benzofurazan N-oxides as synthetic precursors. Part 2. Conversion of benzofurazan N-oxides into 2H-benzimidazoles and some unusual reactions of 2H-benzimidazoles
作者:D. W. S. Latham、O. Meth-Cohn、H. Suschitzky、J. A. L. Herbert
DOI:10.1039/p19770000470
日期:——
Benzofurazan N-oxides react with primary nitroalkanes to give 1-hydroxybenzimidazole3-oxides; with secondary nitroalkanes, red 2,2-dialkyl-2H-benzimidazole 1,3-dioxides are formed. The 2H-benzimidazole oxides react as bis-1,3-dipolar nitrones with acetylenic dipolarophiles (methyl acetylenedicarboxylate and benzyne) but undergo a complex series of redox reactions with tetracyanoethylene giving purple