Novel Dimroth Rearrangements of the Benzotriazole System: 4-Amino-1-(arylsulfonylbenzotriazoles to 4-[(Arylsulfonyl)amino]benzotriazoles

Abstract

A variety of mono-and diarylsulfonyl-substituted 4-aminobenzotriazoles were prepared. Thermal rearrangements of 4-amino-1-(arylsulfonyl)benzotriazoles to 4-[(arylsulfonyl)amino]benzotriazoles were observed and confirmed by separation of the rearrangement products. Their structures were characterized by spectral methods and by X-ray crystallography. The rearrangement rates were studied by variable-temperature NMR experiments. Crossover experiments support an intramolecular mechanism involving a heterolytic benzotriazole ring cleavage to form a diazo intermediate followed by recyclization to the 4-amino group. © 1992, American Chemical Society. All rights reserved.