新型高效除草剂噻磺隆合成新工艺

New Methodology for Synthesis of Novel Herbicide Thifensulfuron

介绍了以氯甲酸甲酯和2-羧甲基-3-磺酰氨基噻吩为起始原料合成除草剂噻磺隆的方法。原料2-羧甲基-3-磺酰氨基噻吩与氯甲酸甲酯生成2-甲氧羧基-3-磺酰氨基甲酸甲酯噻吩,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、含量高和成本低的特点。以2-羧甲基-3-磺酰氨基噻吩计,总收率为77.73%,原药纯度达到93.6%。

A method for preparation of thifensulfuron from methyl chlorformate and 2-methoxycarbonyl-3-aminosulfonylthiophe as starting material was reported. First, 2-methoxycarbonyl-3-aminosulfonylthiophene reacts with methyl chloroformate to give 2- methoxycarbonyl-3-amlnosulfonyl methyl formatethiophene, then thifensulfuron was obtained after the reaction of the above product with 2-amino-4-methoxy-6-methyl-1,3,5-triazine. This is an economical method to prepare thifensulfuron with high yield and good purity, and it avoids the shortcoming of the isocyanate route. The total yield reaches 77.73% and the purity is 93.6% based on 2- methoxycarbonyl-3- aminosul fonylthiophene.