反应详情

5.60 g (18 mmols) of crude 4-(3-hydroxypropyl)-2-[(2-nitrophenyl)azo]phenol synthesized in Example 5 was dissolved in 18 ml of aqueous solution of 2N sodium hydroxide. Subsequently, 9 ml of previously prepared aqueous solution of 25% sodium hydroxide and 5.4 g (83 mmols) of zinc powder were simultaneously added over a period of about 3 hours. The subsequent treatment was carried out in the same manner as in Example 6, giving 3.92 g of 2-(2H-benzotriazole-2-yl)-4-(3-hydroxypropyl)phenol as pale yellow crystals (yield 72%, purity 89%).