Electrosynthesis of Thiophene-2,3-Dicarboxylic Acid
Thiophene-2,3-dicarboxylic acid was synthesized from 3-methylthiophene by three steps of electrohalogenation,Grignard reaction and indirect electrooxidation.The effects of current density and temperature on the yield of 2-bromo-3-methyl thiophene during electro-halogenation were investigated.In this process,sodium bromide is used as the electrohalo-genating reagent,which not only achieves 85.5%yield,but also can better satisfy the study of substrate activity in Grignard reaction.3-Methyl-2-thiophene carboxylic acid was synthe-sized by grignard reaction.The relationship between reaction time and yield was investiga-ted.The optimum reaction time was 6 h,and the yield was 87.8%.Thiophene-2,3-dicar-boxylic acid was synthesized by indirect electrooxidation method.The effects of current den-sity,electrolytic temperature,matrix oxidation temperature,feed ratio and reaction time on the reaction were investigated.The yield of thiophene-2,3-dicarboxylic acid was 87.6%un-der the optimum process.The whole process of electrosynthesis of thiophene-2,3-dicarbox-ylic acid does not use traditional toxic and harmful halogenating agents and oxidants,which is environmentally friendly,less three wastes discharge,simple process,easy product sepa-ration,and can obtain higher products yield.
NETL
NSTL
万方数据
