Preparation method of letrozole key intermediate

The invention provides a preparation method of a letrozole key intermediate (I). 2-(4-cyano-phenyl) glyoxalic acid (II) and 4-halogeno benzene cyanophenyl (III) serve as raw materials, and one-step reaction is performed to generate a target product under the condition of alkali, solvents and catalysts. The preparation method is novel in route, simple and controllable in operation, high in reactionfield and economical, subsequent preparation of high-purity letrozole can be ensured, and industrial large-scale production of the high-purity letrozole is guaranteed. 本发明提供种来曲唑关键中间体(I)的制备方法，以2-(4-氰基苯基)甲酰甲酸(II)、4-卤代苯腈(III)为原料，在碱、溶剂和催化剂条件下，步反应生成目标产物。该制备方法路线新颖，操作简单可控，反应收率高，经济节约，并可确保后续制备得到高纯度的来曲唑，为高纯度的来曲唑的工业上规模化放大生产提供了保障。