One-pot hydrogen peroxide and hydrohalic acid induced ring closure and selective aromatic halogenation to give new ring-fused benzimidazoles.

Abstract

A new series of selectively dichlorinated and dibrominated five- to eight-membered-ring [1,2-a]-fused benzimidazoles and [1,4]oxazino[4,3-a]benzimidazoles are synthesized in mostly high yields of >80% using the reaction of hydrogen peroxide and hydrohalic acid with commercially available o-cyclic amine substituted anilines. Domestic bleach with HCl can also be used for a one-pot ring closure and chlorination.