2-甲基-4-三氟甲基-5-噻唑甲酸的合成工艺改进

Process Improvement on Synthesis of 2-Methyl-4Trifluoro-Methyl-5-Thiazolyl Acid

以三氟乙酰乙酸乙酯2与硫酰氯反应生成2-氯-4,4,4-三氟乙酰乙酸乙酯3,3与硫代乙酰胺在乙腈中及三乙胺存在下反应得到2-甲基-4-三氟甲基-5-噻唑甲酸乙酯4,4经碱水解再酸化得到2-甲基-4-三氟甲基-5-噻唑甲酸1,总收率72.3%,1的结构经IR、MS和1H-NMR的表征。

2-chloro-4,4,4-trifluoro-acetyl ethyl acetate 3 was obtained by 4-trifluoroacetyl ethyl acetate 2 and sulfuryl chloride,2-methyl-4-trifluoro-methyl-5-thiazolyl acid 1 in total yield of 72.3% was obtained by acidification of 2-ethyl-4-trifluoro-methyl-5-thoxycarbonylthiazole 4 which was synthesized by 3 and thioacetamide in acetonitrile with triethylamine.The structure of 1 was confirmed by 1↑H NMR,IR and MS.