Metabolism-directed optimization of 3-aminopyrazinone acetamide thrombin inhibitors. Development of an orally bioavailable series containing P1 and P3 pyridines.
Burgey, C.S., Robinson, K.A., Lyle, T.A., Sanderson, P.E., Lewis, S.D., Lucas, B.J., Krueger, J.A., Singh, R., Miller-Stein, C., White, R.B., Wong, B., Lyle, E.A., Williams, P.D., Coburn, C.A., Dorsey, B.D., Barrow, J.C., Stranieri, M.T., Holahan, M.A., Sitko, G.R., Cook, J.J., McMasters, D.R., McDonough, C.M., Sanders, W.M., Wallace, A.A., Clayton, F.C., Bohn, D., Leonard, Y.M., Detwiler Jr., T.J., Lynch Jr., J.J., Yan, Y., Chen, Z., Kuo, L., Gardell, S.J., Shafer, J.A., Vacca, J.P.J.(2003) J Med Chem 46: 461-473
- PubMed: 12570369 
- DOI: https://doi.org/10.1021/jm020311f
- Primary Citation of Related Structures:  
1MU6, 1MU8 - PubMed Abstract: 
Recent efforts in the field of thrombin inhibitor research have focused on the identification of compounds with good oral bioavailability and pharmacokinetics. In this manuscript we describe a metabolism-based approach to the optimization of the 3-(2-phenethylamino)-6-methylpyrazinone acetamide template (e.g., 1) which resulted in the modification of each of the three principal components (i.e., P1, P2, P3) comprising this series. As a result of these studies, several potent thrombin inhibitors (e.g., 20, 24, 25) were identified which exhibit high levels of oral bioavailability and long plasma half-lives.
Organizational Affiliation: 
Departments of Medicinal Chemistry, Biological Chemistry, Drug Metabolism, Molecular Systems, Structural Biology, and Pharmacology, Merck Research Laboratories, West Point, Pennsylvania 19486, USA. christopher_burgey@merck.com