以水合肼为还原剂,用偶合物合成了2-(2′-羟基-5′-甲基苯基)苯并三唑-N-氧化物。考察了原料比,氢氧化钠用量及浓度等因素对产品收率的影响。得到了适宜的反应条件:偶合物、水合肼与氢氧化钠的摩尔比为1∶0.53∶5.3,氢氧化钠溶液的浓度为18%,反应温度80~82℃,收率达95%以上,纯度为99%。 2- (2’-hydroxy-5’-methylphenyl) benzotriazole-N-oxide was synthesized from the conjugate using hydrazine hydrate as the reducing agent. The effect of raw material ratio, sodium hydroxide dosage and concentration on product yield was investigated. The reaction conditions were as follows: the molar ratio of hydrazine hydrate to sodium hydroxide was 1: 0.53: 5.3, the concentration of sodium hydroxide solution was 18%, the reaction temperature was 80 ~ 82 ℃ and the yield was over 95% Purity is 99%.