碳酸二甲酯作甲基化试剂催化合成2-甲硫基苯并噻唑  

Synthesis of 2-(methylthio)benzothiazole by methylation of 2-mercaptobenzothiazole with dimethyl carbonate via phase-transfer catalytic reaction

作　　者：谢建刚[1,2] 吴承尧[1] 李树白[1] 权静[1] 郑妍[1] 朱利民[1] 

机构地区：[1]东华大学化学化工与生物工程学院,上海201620 [2]郑州师范高等专科学校化学系,河南郑州450044

出　　处：《化学试剂》2010年第9期779-782,共4页Chemical Reagents

基　　金：国家自然科学基金资助项目(50773009);中央高校基本科研业务费专项资金

摘　　要：研究了在四丁基溴化铵(Bu4NBr)与K2CO3催化下,2-巯基苯并噻唑(MBT)与碳酸二甲酯(DMC)合成标题化合物的反应。考察了反应的物料配比、反应时间、反应温度及碱试剂种类和用量对反应的影响。得出甲基化反应最佳配比为:n(MBT)∶n(DMC)∶n(K2CO3)∶n(Bu4NBr)=1∶18∶1.5∶0.2,90℃下反应3h,收率76.4%。副产物为N-甲基化物,讨论了生成副产物的可能机理。2-（Methylthio）benzothiazole was synthesized from 2-mercaptobenzothiazole（MBT）and dimethyl carbonate（DMC）in the presence of tetrabutylammonium bromide（Bu4NBr）and K2CO3.The optimal reaction was carried out at a,temperature of 90 ℃ under atmospheric pressure for 3 h at a ratio of n（MBT）∶n（DMC）∶n（K2CO3）∶n（Bu4NBr）=1∶18∶1.5∶0.2.The yield of 2-（methylthio）benzothiazole was 76.4% under these conditions.Meanwhile,the results of GC-MS analyses showed that the byproduct was a N-methylated derivative.The possible mechanism for formation of N-methylated derivative and the effect of by product formation on the yield of 2-（methylthio）benzothiazole were discussed.

关 键 词：2-巯基苯并噻唑 碳酸二甲酯 四丁基溴化铵 2-甲硫基苯并噻唑 

分 类 号：O626[理学—有机化学]