Pyrido(2,3-d)pyrimidin-7(8H)-one, 6-Acetyl-8-cyclopentyl-5-methyl-2-((5-(1-piperazinyl)-2-pyridinyl)amino)-
6-acetyl-8-cyclopentyl-5-methyl-2-(5-piperazin-1-ylpyridin-2-ylamino)-8H-pyrido(2,3-d)pyrimidin-7-one