An improved process for the production of 2-aryl-2H-benzotriazoles by the reduction of o-nitroazobenzene intermediates with zinc in alkaline medium comprises employing a ratio of moles of alkali to moles of o-nitroazobenzene intermediate in the range of 0.2-1.7/1 in the presence of less than 150 ppm of iron based on zinc used. The improved process results in higher yields of high purity products with a concomitant reduction in the amount of undesired cleavage amine by-products and a reduction in effluent pollution problems. The process is carried out in a polar/non-polar solvent mixture.
一种改进的生产2-芳基-2H-苯并三唑的工艺,通过在碱性介质中使用碱与o-硝基
偶氮苯中间体的摩尔比在0.2-1.7/1的范围内,与使用不超过150ppm基于使用的
锌的
铁,以
锌还原中间体。改进的工艺可以获得高纯度产品的较高产率,同时减少不希望的裂解胺副产物的数量和排放污染问题。该工艺在极性/非极性溶剂混合物中进行。