【摘要】 实验以焦性没食子酸为原料,经醚化、溴代、氰化和水解等合成2,3,4-三甲氧基苯甲酸。在醚化过程中,以离子液体为催化剂,碳酸二甲酯为甲基化试剂,合成连三苯甲醚,收率为92%;连三苯甲醚经NBS溴代反应,合成2,3,4-三甲氧基溴苯,收率为92.2%;2,3,4-三甲氧基溴苯与氰化亚铜反应,合成2,3,4-三甲氧基苯腈,收率为69.5%;2,3,4-三甲氧基苯腈水解合成2,3,4-三甲氧基苯甲酸,收率为80%。更多还原

【Abstract】 2,3,4-Trimethoxybenzic acid(TMBA) was prepared from pyrogallic acid(PA) through a new route,namely etherification,bromination,cyanogenation,and then hydrolysis.PA reacted with dimethyl carbonate with an ionic liquid as catalyst.The yield of the obtained 1,2,3-trimethoxybenzene reached 92%.1,2,3-trimethoxybenzene converted to 2,3,4-trimethoxy bromobenzene with NBS.The yield of the obtained 2,3,4-trimethoxy bromobenzene was 92.2%based on 1,2,3-trimethoxybenzene. 2,3,4-trimethoxy bromobenzene reacted with cuprous cyanide in the presence of DMF as solvent.The yield of the obtained 2,3,4-trimethoxy cyanobenzene was 69.5%.TMBA was prepared by hydrolysis and acidification with the yield of 80%.The total yield of TMBA by this route was 47.2%based on PA.更多还原