4-氯-5-硝基-2-氨基苯酚的合成

Synthesis of 4-Chloro-5-nitro-2-aminophenol

本文以4-氯-2-氨基苯酚为起始原料合成了4-氯-5-硝基-2-氨基苯酚。4-氯-2-氨基苯酚经醋酐酰化制得2-乙酰氨基-4-氯苯酚,粗产率为92.4％,熔点为170.3℃～171 3℃。然后分别以氯苯,邻二氯苯为脱水剂在回流条件下反应15小时,经真空蒸馏得到5-氯-2-甲基苯并(?) 唑,熔点为52℃-54℃。将5-氯-2-甲基苯并(?)唑进行硝化反应,得到5-氯-6-硝基-2-甲基苯并(?)唑,粗产率84.76％,熔点为135.5℃-139.0℃。5-氯-6-硝基-2-甲基苯并(?)唑在强碱条件下水解后,经酸析得到4-氯-5-硝基-2-氨基苯酚,粗产率为90.10％.熔点为209.8～210.0℃。

This paper describes the synthesis of 4-chloro-5-nitro-2-aminophenol from the starting material 4-chloro-2-aminophenol. The process included four steps. Firstly, 4-chloro-2-acetaminophenol was prepared by acetylating 2-amino-4-chlorophenol. Secondly, 2-methyl-5-chlorobenzoxazole was obtained by refluxing 4-chloro-2-acetaminophenol with chlorobenzol or o-dichlorobenzene mixture for 15 hours and then distilling the resultant mixture in vacuum. Thirdly, nitrating 2-methyl-5-chlorobenzoxazole with mixed acid to give 2-methyl 5-chloro-6-nitro benzoxazole with a yield of 84.7%, melting point 135.3~139.0℃.Lastly, hydrolyzing 2-methyl-5-chloro-6-nitrobenzoxazole in strong alkaline solution and neutralizing the resultant mixture with hydrochloric acid, 4-chloro-5-nitro-2-aminophenol was obtained with a melting point 209.8 ~210.0℃ and yield 90.10%.