反应详情

5.91 g (18 mmols) of crude 4-(2-hydroxyethyl)-2-[(4-chloro-2-nitrophenyl)azo]phenol synthesized in Example 4 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 4.02 g of 2-(5-chloro-2H-benzotriazole-2-yl)-4-(2-hydroxyethyl)phenol as pale yellow crystals (yield 68%, purity 88%).