3,5-二氯-4-氟三氟甲苯的合成

Synthesis of 3,5-dichloro-4-fluoro-trifluorotoluene

目的研究3,5-二氯-4-氟三氟甲苯的合成工艺。方法以3,4,5-三氯-三氟甲苯和氟化钾为原料通过相转移催化合成目标产物。结果确定了反应的最佳条件为反应物物质的量比n(3,4,5-三氯-三氟甲苯)∶n(氟化钾)=1∶1.5,催化剂与原料质量比m(PEG-600)∶m(原料)=0.5～0.7∶100,原料与溶剂环丁砜(TMSO2)体积比为1∶3～3.5,190～195℃反应12 h,原料转化率大于87%,收率80%,产品纯度大于98%(质量分数)。结论为工业化生产3,5-二氯-4-氟三氟甲苯提供了依据。

Aim To research the synthesis process of 3,5-dichloro-4-fluoro-trifluoro-toluene.Methods The title compound was synthesized from 3,4,5-dichloro-trifluoro-toluene and KF by phase transfer catalysis.Results Using TMSO2 as solvent,mole ratio n（3,4,5-trichlorobenzotrifluride）∶ n（KF）=1∶ 1.5,weight ratio m（PEG-600）∶ m（3,4,5-trichloro-benzotrifluoride）=0.5～0.7∶ 100,volume ratio V（3,4,5-trichlorobenzotrifluoride）： V（TMSO2）=1∶ 3～3.5,stirring for 12h at 190～195℃,the conversion of 3,4,5-trichlorobenzotrifluoride is 87%,the yield is 80%,and the content is more than 98%.Conclusion The process was mild and available for synthesis of 3,5-dichloro-4-fluoro-trifluorotoluene.