Abstract: 3-Dichloromethyl-1-methyl-4-cyanide-1H-pyrazol is the key intermediate for synthesizing difluoro-pyrazole carboxamide series bactericides.It is prepared via two-step pipeline continuous reaction including addition-elimination reaction and cyclization reaction,with 3-(dimethylamino)acrylnitrile and dichloroacetyl chloride as raw materials.The reaction process is optimized to obtain the optimum reaction conditions as follows:addition-elimination reaction for 30 s at 0℃ and cyclization reaction for 90 s at 0℃.Under these optimal process conditions,the total yield after two-step reactions reaches 93.5%,the gas chromatograph content of the product is 97.2%,the content of isomers is less than 0.1% isomer and the reaction yield is 5% higher than that of the kettle type reaction.
杜友兴, 孙天孜, 何立. 3-(二氯甲基)-1-甲基-4-氰基-1H-吡唑的连续化合成[J]. 现代化工, 2018, 38(8): 198-201,203.
DU You-xing, SUN Tian-zi, HE Li. Continuous synthesis of 3-(dichloromethyl)-1-methyl-4-cyanide-1H-pyrazole. Modern Chemical Industry, 2018, 38(8): 198-201,203.