磺草酮中间体3-氯-4-甲基苯甲砜的合成

Synthesis of 3-Chloro-4-methyl-methylsulfonylbenzene as an Intermediate of Sulcotrione

以对甲苯磺酰氯为起始原料,经氯化、还原和烷基化3步反应,合成了玉米田高效除草剂磺草酮中间体3-氯-4-甲基苯甲砜。研究了反应温度、反应时间、原料配比和催化剂等因素对反应收率的影响。在最佳工艺条件下,即摩尔比分别是对甲苯磺酰氯∶三氯化锑为70∶1,三氯化锑∶碘为7∶1时,于75℃～80℃通氯反应3h,得3-氯-4-甲基苯磺酰氯;亚硫酸钠∶氯乙酸钠∶3-氯-4-甲基苯磺酰氯为1.1∶1.5∶1时,先于75℃～80℃还原反应4h,再于103℃～106℃回流反应20h,得3-氯-4-甲基苯甲砜,3步反应的总收率为91.2%,产物纯度为99.5%。

3-Chloro-4-methyl-methylsulfonylbenzene, an intermediate of sulcotrione, was synthesized using 4-methylbenzenesulfonyl chloride as a primary material, following by chlorination, reduction and alkylation. The influence on reaction temperature, reaction time, reactant ratio and catalyst was investigatd. The optimum reaction conditions are as follows： the chlorinating reaction was carried out at a molar ratio of 4-methylbenzenesulfonyl chloride/ antimony trichloride was 70：1 and antimony trichloride/iodine was 7：1 for 3 h at 75-80℃. The reducting and alkylating reactions were carried out at a molar ratio of sodium sulfite/sodium choloacetate/3-chloro-4-methyl- benzenesulfonyl chloride was 1.1 ： 1.5 ： 1 for 4h at 75-80℃ and for 20 h at 103-106 ℃ respectively with a total yield of 91.2% and a purity of 99.5% in the preparation of 3-chloro-4-methyl-methylsulfonylbenzene.