How is 2-Hydroxyethanesulfonic acid - 6-acetyl-8-cyclopentyl-5-methyl-2-{[5-(1-piperazinyl)-2-pyridinyl]amino}pyrido[2,3-d]pyrimidin-7(8H)-one (CAS: 827022-33-3) typically synthesized?

2-Hydroxyethanesulfonic acid - 6-acetyl-8-cyclopentyl-5-methyl-2-{[5-(1-piperazinyl)-2-pyridinyl]amino}pyrido[2,3-d]pyrimidin-7(8H)-one is typically synthesized via a multi-step process involving the formation of an acetyl derivative, cyclization, and subsequent modification with piperazine and pyridine groups. Commonly used reagents include acetic anhydride, piperazine, and 2-methyl-5-(2-pyridyl)-1H-pyrimidine-4,6(1H,5H)-dione, with high selectivity and good yields achievable under optimized reaction conditions.