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作 者:陈健[1] 杨运泉[1] 罗和安[1] 段正康[1] 刘文英[1]
出 处:《精细化工》2007年第2期169-171,共3页Fine Chemicals
基 金:湖南省科技厅科技攻关项目(04FJ4116)
摘 要:以3,4,5-三甲氧基甲苯(TMT)为原料,先由V ilsm e ier-Haack反应合成6-甲基-2,3,4-三甲氧基苯甲醛,然后在对甲基苯磺酸催化下经Dak in反应将其氧化为6-甲基-2,3,4-三甲氧基苯酚,最后用重铬酸钠催化氧化合成了辅酶Q0,过程总收率达到72.3%。经正交实验得V ilsm e ier-Haack反应的最佳工艺为:n(TMT)∶n(POC l3)∶n(DMF)=1∶1.8∶2.2,反应温度70℃,反应时间7 h。在此工艺条件下,此步反应收率可达93.2%,w(6-甲基-2,3,4-三甲氧基苯甲醛)=98.5%;在Dakin反应中,以w(H2O2)=30%为氧化剂,30℃为最佳反应温度,反应时间1.5 h。Coenzyme Q0 ( 2,3-dimethoxy-5-methyl-1,4-benzoquinone ) was synthesized through threestep process employing 3,4,5-trimethoxytoluene ( TMT ) as the starting material. The first step, involving Vilsmeier-Haack reaction, gave 6-methyl-2, 3,4-trimethoxybenzaldehyde. The next step, involving Dakin Reaction with p-toluensulfonic acid as the catalyst, gave 6-methyl-2, 3, 4- trimethoxypenol. In the last step, Coenzyme Q0 was prepared through catalytic oxidation with sodium dichromate as the oxidant. The overall yield reached 72. 3% (based on TMT). The most favorite technological conditions of Vilsmeier-Haack Reaction are : n (TMT) : n ( POCl3 ) : n (DMF) = 1 : 1.8: 2. 2, 70℃ and 7 h. Under the optimum conditions ,a yield of 93.2% with the purity of 98.5% in Vilsmeier-Haack reaction was obtained. For Dakin reaction, reaction temperature is the major effective factor, and the optimal reaction temperature and reaction time are 30℃ and 1.5 h respectively.
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