LAUSR

An operationally simple method has been developed for the preparation of N‐unsubstituted benzotriazoles by diazotization and intramolecular cyclization of a wide range of 1,2‐aryldiamines under mild conditions, using a polymer‐supported nitrite reagent and p‐tosic acid. The functional group tolerance of this approach was further demonstrated with effective activation and cyclization of N‐alkyl, ‐aryl, and ‐acyl ortho‐aminoanilines leading to the synthesis of N1‐substituted benzotriazoles. The synthetic utility of this one‐pot heterocyclization process was exemplified with the preparation of a number of biologically and medicinally important benzotriazole scaffolds, including an α‐amino acid analogue.