Oxidative Cyclization of 4‐(2‐Mercaptophenyl)‐Substituted 4H‐1,2,4‐Triazolium Species to Tricyclic Benzothiazolium Salts

Abstract

AbstractHerein we report a generally applicable method for the preparation of N‐substituted benzo[4,5]thiazolo[2,3‐c][1,2,4]triazol‐1‐ium salts from air stable precursors. This transformation features selective deprotection of a para‐methoxybenzyl protected thiol followed by C−H functionalization of the linked 1,2,4‐triazolium salts under oxidative conditions. Using this procedure, we synthesized a variety of tricyclic thiazolium salts which contain both electron‐withdrawing and electron‐donating aromatic substituents as well as aliphatic substituents. Our approach also tolerates many functional groups including alkynes, alcohols, diols, amides, and polyethers.