3,6-二氯水杨酸O-甲基化工艺的研究

Study on O-Alkylation for Synthesis of 3,6-Dichlorosalicylic Acid by Chloromethane

探讨了以 3,6 -二氯水杨酸为原料 ,经O -甲基化反应合成 3,6 -二氯 - 2 -甲氧基苯甲酸的工艺。通过正交实验得到了O -甲基化反应的最佳工艺条件为 :n(3,6 -二氯水杨酸 )∶n(氢氧化钠 ) =1∶4 .5 ,反应温度 10 0℃ ,反应压力 0 .6MPa ,保温时间 6h ,在此条件下 ,O -甲基化收率为 92 .6 %

The O-alkylation of 3,6-dichlorosalicylic acid by chloromethane is studied.By orthogonal test,the optimal reaction condition is determined:temperature 100℃,pressure 0.6MPa, the molecular ratio of 3,6-dichlorosalicylic acid to sodium hydroxide 1∶4.5,the time of constant-temperature 6h is determined . The yield of 2-methoxy-3,6-dichlorobenzoic acid reaches 92.6%.