The Cycloaddition Reactions of Benzimidazole-2-carbonitrite Oxide With Alkenes

Abstract

Benzimidazole-2-carbonitrile oxide was prepared in situ and reacted with vinyl acetate, acrylonitrile, styrene, phenyl vinyl sulfone and 3,3,3-trifluoropropene to afford 2-(5'-acetoxyisoxazolin-3'-yl)-, 2-[(5'-cyanoisoxazolin-3'-yl)-, 2-(5'-phenylisoxazolin-3'-yl)-, 2-[(5'-phenylsulfonyl)isoxazolin-3'-yl]- and 2-[(5'- ( trifluoromethyl )isoxazolin-3'-yl)]- benzimidazole respectively. 2-(5'-Acetoxyisoxazolin-3'-yl) benzimidazole was converted into 2-(isoxazol-3'-yl) benzimidazole by treatment with triethylamine. The amidoximes derived from unsubstituted and N¹-sulfamoyl-substituted 2-cyanobenzimidazoles were prepared but were not preparatively useful as precursors to benzimidazole-2-carbonitrile oxides.