Molecular Formula: C26H35N7O6S Formula Weight: 573.664
6-acetyl-8-cyclopentyl-5-methyl-2-[[5-(1-piperazinyl)-2-pyridinyl]amino]pyrido[2,3-d]pyrimidin-7(8H)-one 2-hydroxy-ethanesulfonic acid (1:1);Palbociclib isethionate