A route for cyclization reaction of N-allyl-N′-benzylideneacetohydrazide and ethyl 2-bromo-2,2-difluoroacetate to synthesize 3-(1-acetyl-3-phenyl-4,5-dihydro-1H-pyrazol-4-yl)-2,2-difluoropropanoate has been developed. This methodology features mild reaction conditions and good functional group tolerance, providing a direct approach for the preparation of dihydropyrazoles.

中文翻译：

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N-烯丙基-N'-亚苄基乙酰肼和2-溴-2乙酯合成3-(1-乙酰基-3-苯基-4,5-二氢-1H-吡唑-4-基)-2,2-二氟丙酸乙酯,2-二氟乙酸酯

N-烯丙基-N'-亚苄基乙酰肼与2-溴-2,2-二氟乙酸乙酯环合合成3-(1-乙酰基-3-苯基-4,5-二氢-1H-吡唑-4-)的路线yl)-2,2-二氟丙酸酯已被开发出来。该方法反应条件温和，官能团耐受性好，为二氢吡唑的制备提供了直接途径。