5-甲基-1,3,4-噁二唑-2(3H)-酮的合成新方法

New Synthesis Method of 5-Methyl-1,3,4-oxadiazol-2(3H)-one

以乙酸和水合肼为原料,经两步反应得到吡蚜酮的重要中间体5-甲基-1,3,4-噁二唑-2(3H)-酮。第一步反应中使用ZnCl_2/凹土固载催化剂,缩短了反应时间,提高了反应收率,第二步反应中使用Na_2CO_3为缚酸剂,环己烷为溶剂。总收率达83.4%。目标化合物经IR、~1HNMR确证。

5- Methyl- 1,3,4- oxadiazol- 2 （3H） -one, an intermediate of pymetrozine for pesticide, was synthesized by two steps with acetic acid and hydrazine hydrate as raw materials. In step one, reaction time was reduced and the yield was increased by employing immobilized ZnCl2/attapulgite catalyst. In step two, Na2CO3 was employed as the acid -binding agent and cyclohexane was employed as the solvent. Under optimum conditions,the total yield was up to 83.4%. The target compound was confirmed by IR and 1HNMR.