A simple, versatile synthetic route to N-1-aryl-, -heteroaryl-, -acylmethyl-, -carboxymethyl- and -alkyl-benzotriazoles via regiospecific or highly regioselective substitutions of benzotriazole

Article abstract of DOI:10.1055/s-1994-25530

In the absence of any added base in refluxing benzene or toluene, benzotriazole replaces the halogen atom of an α-halogenated ketone or a carboxylic ester to give the corresponding N-1-substituted benzotriazole as the only isomer. 2-Bromopyridine and 1-chloro-2,4-dinitrobenzene reacted similarly with benzotriazole to afford the corresponding N-1-substituted benzotriazole derivatives in quantitative yields. Alkyl halides reacted regioselectively to afford the N-1-alkylbenzotriazoles in ratios of more than 10 to 1 over the N-2 isomers. An α-(benzotriazol-1-yl)carboxylic ester was hydrolyzed into the corresponding carboxylic acid, which upon heating underwent smooth decarboxylation into the corresponding 1-alkylbenzotriazole.