四步法合成2-乙基-4-甲氧基苯胺  

Synthesis of 2-Ethyl-4-Methoxy Aniline Via Four-Step Process

作　　者：郭翔海[1] 司爱华[1] 刘益群[2] 

机构地区：[1]天津大学药物科学与技术学院,天津300072 [2]天津药物研究院,天津300193

出　　处：《石油化工》2007年第6期605-609,共5页Petrochemical Technology

摘　　要：以氯霉素的副产物邻硝基乙苯为原料,经Bamberger反应、乙酰化反应、o-甲基化反应和水解反应4步合成了可作为5-甲氧基吲哚合成原料的2-乙基-4-甲氧基苯胺;对该工艺路线的关键步骤Bamberger反应进行了工艺条件优化。实验结果表明,邻硝基乙苯经4步反应后,2-乙基-4-甲氧基苯胺的总收率为55%左右;Bamberger反应的优化条件为:以硫酸溶液为介质,[H+]为4.42mol/L,Pt/C催化剂质量分数为1.84%(基于邻硝基乙苯的质量),在此条件下,Bamberger反应产物3-乙基-4-氨基苯酚的收率可达81.7%;硫酸中加入磷钼酸不利于羟基苯胺中间体的稳定存在。同时还对各步反应产物进行了红外光谱和核磁共振表征,确定了各步反应的产物结构。2 -Ethyl-4 -methoxy aniline was synthesized from o -nitroethylbenzene, a byproduct from chloramphenicol industry, through a four - step process including Bamberger reaction, acetylation, o - methylation and hydrolysis. Product 2 - ethyl - 4 - methoxy aniline is considered as a promising raw material with big potential for producing 5 -methoxy indole, an important fine chemical used in synthesis of indole derivatives. Total yield of 2 - ethyl - 4 - methoxy aniline at the end of four step process is about 55 %. The Bamberger reaction is the key step. The optimal conditions for the key step are as follows ： sulfuric acid as reaction medium, [ H^＋ ] 4.42 mol/L and mass fraction of Pt/C catalyst 1.84 % （ based on o - nitroethylbenzene）. Yield of this key step product - 3 - ethyl - 4 - amino phenol is 81.7%. Addition of phosphomolybdic acid to H2SO4 is not favorable to stability of intermediate hydroxylamine. Structures of product and all intermediates were identified and confirmed by means of IR and NMR.

关 键 词：邻硝基乙苯 2-乙基-4-甲氧基苯胺 5-甲氧基吲哚 Bamberger反应 催化剂 

分 类 号：TQ032.4[化学工程]