5-丙氧基-4-甲基-1,2,4-三唑啉酮的合成

Synthesis of 5-Propoxy-4-methyl-1,2,4-triazol-3-one

5-丙氧基-4-甲基-1,2,4-三唑啉酮是新型磺酰脲类除草剂——丙苯磺隆的关键中间体。以氯甲酸乙酯和硫氰化钠为起始原料,常温反应得到中间体化合物Ⅰ,然后将其与硫酸二甲酯反应得到中间体化合物Ⅱ,再经水合肼环化得到中间体化合物Ⅲ,最后经硫酸二甲酯甲基化后得到目标化合物Ⅳ。以上各步收率适中。中间产物及目标产物的结构经过熔点1、HNMR和MS表征。该法具有成本低、工业化生产相对安全、易操作的优点。

5-Propoxy-4-methyl-1,2,4-triazol-3-one is the key intermediate for preparing sulfonylurea herbicide——procarbazone.In order to simplify technological conditions and reduce production cost,a new synthetic route was reported.Using ethyl chloroformate and sodium thiocyanate as starting materials,the intermediate Ⅰ was obtained at room temperature and the intermediate Ⅱ was obtained by reaction of methyl sulfate and Ⅰ.After cyclization of Ⅱ by hydrazinehydrate and methylation of the intermediate Ⅲ using methyl sulfate,the target compound Ⅳ was obtained.The yields of above steps were moderate.The intermediates Ⅰ~Ⅲ and target compound Ⅳ were confirmed by MS,1HNMR.This method was suitable for industrial production.