中间体3-氯-1-(3-吡啶基)-4,5-二氢-1H-吡唑的合成工艺研究

Study on the synthesis of intermediates 3-chloro-1-(3-pyridinyl)-4,5-dihydro-1H-pyrazole

3-氯-1-(3-吡啶基)-4,5-二氢-1H-吡唑是合成新型吡啶基吡唑类杀虫剂Tyclopyrazoflor(GF-3242)的关键中间体,按照优选出的合成工艺路线进行了中间体3-氯-1-(3-吡啶基)-4,5-二氢-1H-吡唑的合成即以3-肼基吡啶盐酸盐作为起始物料进行环化和氯化反应得到产品3-氯-1-(3-吡啶基)-4,5-二氢-1H-吡唑。通过对3-羟基-1-(3-吡啶基)-4,5-二氢-1H-吡唑的合成工艺进行优化实验:3-肼基吡啶盐酸盐:丙烯酸甲酯=1∶2为最佳的物质的量比,6 h为最佳反应时间,55~60℃为最佳反应温度,收率最高为90.02%;对3-氯-1-(3-吡啶基)-4,5-二氢-1H-吡唑的合成进行优化实验:3-羟基-1-(3-吡啶基)-4,5-二氢-1H-吡唑∶三氯氧磷=1:0.66为最佳的物质的量比,3 h为最佳反应时间,55~60℃为最佳反应温度,收率最高为85.08%。

3-chloro-1-(3-pyridinyl)-4,5-dihydro-1H-pyrazole is a key intermediate of Tyclopyrazoflor(GF-3242)which is a new pyridinyl-pyrazole insecticide,according to the optimized synthetic process route of 3-chloro-1-(3-pyridinyl)-4,5-dihydro-1H pyrazole.3-hydrazinopyridine hydrochloride as the starting material by cyclization and chlorination reaction to synthesize 3-chloro-1-(3-pyridyl)-4,5-dihydro-1H-pyrazole.The synthesis of 3-hydroxy-1-(3-pyridinyl)-4,5-dihydro-1h-pyrazole was optimized:3-hydrazino-pyridine hydrochloride:methyl acrylate=1:2 is the best volume ratio of substance,6 hours is the best reaction time,55~60℃ is the best reaction temperature,and the highest yield was up to 90.02%.The synthesis of 3-chloro-1-(3-pyridinyl)-4,5-dihydro-1H-pyrazole was optimized:3-hydroxy-1-(3-pyridinyl)-4,5-dihydro-1H-pyrazole:Phosphorus oxychloride=1:0.66 was the best volume ratio of substance,3 hours was the best reaction time,55~60℃was the best reaction temperature,and the highest yield was up to 85.08%.