Benzotriazol‐1‐ylmethylamines on treatment with alkylating agents afford benzotriazol‐1‐ylmethylammoni‐um salts, also available from reactions of chloromethylbenzotriazole with tertiary amines. In deuterated solvents under basic conditions the methylene protons of these salts exchange with deuterium. At elevated temperatures, an alkyl group substituent migrated from the ammonium center to the benzotriazolyl N‐3. Reactions of the salts with Grignard reagents afforded various products arising from substitution of the ammonium moiety and/or from attack on the benzotriazolyl N‐3 or on the benzenoid ring.

ChemInform Abstract Benzotriazole (I) is used for the two-step preparation of N-monosubstituted sulfonamides, e.g. (V) and (VII).