Imidazoles: SAR and development of a potent class of cyclin-dependent kinase inhibitors.

An imidazole series of cyclin-dependent kinase (CDK) inhibitors has been developed. Protein inhibitor structure determination has provided an understanding of the emerging structure activity trends for the imidazole series. The introduction of a methyl sulfone at the aniline terminus led to a more orally bioavailable CDK inhibitor that was progressed into clinical development.