ULIPRISTAL ACETATE PREPARATION METHOD AND INTERMEDIATE THEREOF.

摘要

Provided are an Ulipristal acetate (compound I) preparation method, a novel key intermediate (compound of formula IV) for preparing the Ulipristal acetate and preparation of the key intermediate. It has been surprisingly found in the present invention that the novel intermediate of formula IV facilitates the reaction with methyllithium or the methyl Grignard reagent; the protective group can be easily removed after the reaction, with fewer side reactions and simple intermediate treatment; the reagent used is readily available, with low cost and high yield; a compound of formula III is firstly prepared into an intermediate of formula IV, and the intermediate is then prepared into a compound of formula V; the total yield of the two steps is as high as 75%, with the product purity more than 98%. R in the formula is as defined in the specification.