2,3,4,5-四甲氧基甲苯选择性O-去甲基化和催化氧化合成辅酶Q_0  

Synthesis of Coenzyme Q_0 by Selective Catalytic O-Demethylation of 2,3,4,5-Tetramethoxytoluene and Catalytic Oxidation

作　　者：杨运泉[1] 罗和安[1] 陈田[1] 周国平[1] 刘文英[1] 

机构地区：[1]湘潭大学化工学院,湖南湘潭411105

出　　处：《石油化工》2008年第2期161-164,共4页Petrochemical Technology

基　　金：湖南省科技厅科技攻关项目(04FJ4116)

摘　　要：以Lewis酸为催化剂、冰醋酸为反应介质,对2,3,4,5-四甲氧基甲苯进行选择性O-去甲基化反应,中间产物6-甲基-2,3,4-三甲氧基苯酚不经分离直接加入质量分数30%的双氧水作为氧化剂,以杂多酸为催化剂,经氧化反应合成了辅酶Q0;考察了Lewis酸种类、杂多酸种类、氧化温度对辅酶Q0收率的影响。实验结果表明,2,3,4,5-四甲氧基甲苯进行选择性O-去甲基化反应的适宜条件为:ZnCl2为催化剂,n(ZnCl2)∶n(2,3,4,5-四甲氧基甲苯)=1.5,反应温度125℃,反应时间2h;适宜的氧化反应条件为:以磷钼酸为催化剂,在40℃下反应2h。在此条件下,辅酶Q0的收率为80.0%;经熔点测定、核磁共振和傅里叶变换红外光谱表征,确定产品为辅酶Q0。Coenzyme Q0-- a key intermediate for preparation of coenzyme Q10 was synthesized by selective catalytic O-demethylation of 2,3,4,5-tetramethoxytoluene using Lewis acid as catalyst and followed by catalytic oxidation using heteropolyacid as catalyst. In the former process different Lewis acids were used as catalysts. An intermediate product---6-methyl-3,4,5-trimethoxypenol was obtained and was further oxidized in situ without separation by H2O2 using different heteropolyacids as catalysts to produce the final product Q0. Influencing factors of the two processes were studied. The optimal conditions of O-demethylation are： ZnCl2 as catalyst, CH3COOH as solvent, 125 ℃, 2 h and n（ZnCl2） ： n （2,3,4,5-tetramethoxytoluene） 1.5. The subsequent oxidation of 6-methyl-3,4,5- trimethoxypenol was carded out under the optimal conditions of H2O2 as oxidant, 40 ℃ for 2 h and H3PMo12O40 as catalyst. Yield of obtained coenzyme Q0 is 80.0% under above conditions. The structure of product is identified by means of FTIR and ^1H NMR.

关 键 词：2 3 4 5-四甲氧基甲苯 LEWIS酸 杂多酸 辅酶Q0 双氧水 O-去甲基化 催化氧化 

分 类 号：TQ244.6[化学工程—有机化工]