Novel preparation method of tofacitinib citrate

The invention discloses a novel preparation method of tofacitinib citrate, and particularly provides a preparation method of tofacitinib citrate. The preparation method comprises the following steps:adding a tofacitinib intermediate crude product in a solvent, completely dissolving at a relatively high temperature, and adding medicinal activated carbon and activated aluminum oxide for stirring and adsorption; filtering to remove the medicinal activated carbon and the activated aluminum oxide, adding a pre-cooled alkaline aqueous solution in a filtrate, reducing the temperature to 0-5 DEG C for crystallization, washing and then drying to obtain a tofacitinib intermediate refined product; dissolving citric acid monohydrate in an ethanol aqueous solution, then adding the tofacitinib intermediate refined product and crystallizing to obtain the tofacitinib citrate. The novel preparation method disclosed by the invention has the benefits that hard-to-remove pigments and impurities in the tofacitinib intermediate cr