A ligand-free copper (1) catalysed intramolecular N-arylation of diazoaminobenzenes in PEG-water: an expeditious protocol towards regiospecific 1-aryl benzotriazoles.

An efficient and highly versatile method for the synthesis of diverse regiospecific 1-arylbenzotriazoles being important medicinal scaffolds, by the copper (1) catalysed intramolecular N-arylation of diazoaminobenzenes of 2-haloaryldiazonium salts in PEG-water has been developed. A very simple reaction protocol, large number of substrate affordability and excellent yields are the main features of this methodology.