含二氟溴甲基取代的新型吡唑类化合物的合成

Synthesis of Novel Bromodifluoromethyl Substituted Pyrazole Compounds

以二氟溴乙酸乙酯、水合肼、甲基酮、NCS、NBS等为原料,通过Claisen缩合、关环、卤代等反应合成了12个未见合成文献报道的含二氟溴甲基取代的吡唑类化合物,其结构均通过1HNMR、13CNMR和HRMS表征。合成中对关环条件进行了优化,合成3-二氟溴甲基-5-烷基-1H-吡唑的反应收率均达90%以上。

Twelve novel bromodifluoromethyl substituted pyrazoles were synthesized from starting materials ethyl bromodifluoroace- tare and hydrazine hydrate via claisen condensation,cyclization reactions and NBS or NCS halogenations. The structures were con- firmed by ^1 HNMR,^13CNMR arid HRMS. The conditions of eyclization reaction were optimized, the yields for target compounds 3-bromodifluoromethyl-5-alkyl-1H-pyrazole were above 90%.