3S2P:
reference: Discovery of a novel class of 2-aminopyrimidines as CDK1 and CDK2 inhibitors., Lee J, Kim KH, Jeong S, Bioorg Med Chem Lett. 2011 Jul 15;21(14):4203-5. Epub 2011 May 27. PMID: 21684737

This OCA Structure page
uses Jmol, developed by the Jmol Development Team (documentation).