CRYSTAL FORM OF A CYCLIN-DEPENDENT KINASE INHIBITOR AND THE PREPARATION METHOD THEREOF

摘要

Provided are the crystal form of a cyclin-dependent kinase inhibitor (CDK&6) and a preparation method thereof. In particular, provided are II-type crystals of 6-acetyl-8-cyclopentyl-5-methyl-2-((5-(piperidin-4-yl)pyridin-2-yl) amino)pyridino[2,3-d]pyrimidin-7(8H)-one (compound of formula (I)) and the preparation method thereof, the crystal having an X-ray powder diffraction pattern as shown in figure 1, a good chemical stability and crystal form stability, and using a low toxicity, low residual crystallization solvent, so as to be better used for clinical treatment.