除草剂噻磺隆的合成

Synthesis of Herbicide Thifensulfuron

报道了以氯甲酸甲酯和2-甲氧羰基-3-氨基磺酰基噻吩为起始原料合成除草剂噻磺隆的方法。原料2-甲氧羰基-3-氨基磺酰基噻吩与氯甲酸甲酯生成2-甲氧羰基-3-甲氧羰基氨基磺酰基噻吩,再与2-氨基-4-甲氧基-6-甲基均三嗪反应生成噻磺隆。避免了异氰酸酯路线的种种缺点,具有收率高、含量高、成本低的特点。以2-甲氧羰基-3-氨基磺酰基噻吩计,总收率为77.73%,原药纯度达93.6%。

A method for preparation of thifensulfuron from methyl chloroformate and 2-methoxycarbonyl-3-aminosulfonylthiophene as starting material was reported. 2-Methoxycarbonyl-3-aminosulfonylthiophene reacts with methyl chloroformate to give 2-methoxycarbonyl-3-methoxycarbonyl aminosulfonylthiophene. Thifensulfuron will be obtained by the reaction of the above product and 2-amino-4-methoxy-6-methyl-1,3,5-triazine. This is an economical method to prepare thifensulfuron in high yield and good purity, avoiding the shortcoming of the isocyanate route. The total yield reaches 77.73% based on 2-methoxycarbonyl-3-aminosulfonylthiophene and the purity is 93.6%.