PROCESS FOR THE PRODUCTION OF 2-ARYL-2H- BENZOTRIAZOLES

摘要

A process for the production of 2-aryl-2H-benzotriazoles having the formula I (I) comprises reducing and cyclizing the corresponding o-nitro-azobenzenes having the formula II (II) with hydrogen at a temperature in the range of about 20.degree.C to about 100.degree.C and at a pressure in the range of about 1 atmosphere to about 66 atmospheres in an alkaline medium at a pH over 10 in the presence of a nickel catalyst, preferably molybdenum-promoted Raney nickel. High yields of pure product are obtained directly with a concomitant reduction of undesired by-product and a reduction in effluent pollution problems.