3,4,5-三甲氧基苯乙酸的合成  

Synthesis of 3,4,5-Trimethoxyphenyl Acetic Acid

作　　者：邓旭忠[1] 黄顺[1] 王岳群[1] 

机构地区：[1]广东工业大学轻工化工学院,广东广州510006

出　　处：《精细化工》2011年第12期1240-1243,共4页Fine Chemicals

摘　　要：以3,4,5-三甲氧基苯甲醛为原料,经二氯卡宾反应、还原反应两步合成了米库氯铵的重要中间体——3,4,5-三甲氧基苯乙酸。较佳的合成工艺条件为:(1)二氯卡宾反应:以0.3 mol 3,4,5-三甲氧基苯甲醛为基准,在n(3,4,5-三甲氧基苯甲醛)∶n(CHCl3)=1∶3,复合相转移催化剂(PTC)2 g,w(NaOH)=40%的水溶液21 mL,反应温度60℃,反应时间7 h的条件下,反应收率为71.7%;(2)还原反应:以0.1 mol 3,4,5-三甲氧基扁桃酸为基准,在n(3,4,5-三甲氧基扁桃酸)∶n〔(CH3)3SiCl〕∶n(NaI)∶n(Zn)=1∶1.25∶1.25∶3,反应温度80℃,"一锅法"反应5 h的条件下,反应收率91.0%。两步反应总收率为65.2%。产物结构通过IR、1HNMR进行表征。3,4,5-Trimethoxyphenyl acetic acid, an important intermediate for preparation of mivacurium chloride, was synthesized from 3, 4, 5-trimethoxybenzaldehyde by diehlorocarbene reaction and reduction reaction. The optimum reaction conditions are as follows ： （ 1 ） In dichlorocarbene reaction, the molar ratio of raw materials was n （3,4,5-trimethoxybenzaldehyde） ： n （chloroform） = 1 ： 3 （ based on 0. 3 tool 3,4,5-trimethoxybenzaldehyde） , w （NaOH） = 40% solution was 21 mL, the composite phase transfer catalyst （PTC） was 2 g, reaction time was 7 hours at 60 ℃. The yield of 3, 4, 5- trimethoxymandelic acid was 71.7 %. （2）In reduction reaction, the molar ratio of raw materials was n （3,4,5-trimethoxymandelic acid ） ： n （trimethylchlorosilane） ： n （ sodium iodide） ： n （ zinc ） = 1 ： 1.25 ： 1.25：3 （based on 0. 1 tool 3,4,5-trimethoxymandelic acid）, ＂one-pot＂ reaction time was 5 h at 80 ℃. The yield of the target product was 91.0%. The overall yield of the two steps of reaction reached 65.2% and the structures of the target compound were confirmed by means of IR and 1HNMR.

关 键 词：3 4 5-三甲氧基苯甲醛 二氯卡宾反应 还原反应 3 4 5-三甲氧基苯乙酸 “一锅法”反应 精细化工中间体 

分 类 号：R971.8[医药卫生—药品]