Discovery of potent and selective β-homophenylalanine based dipeptidyl peptidase IV inhibitors

Modification of in-house screening lead beta-aminoacyl proline 8 gave an equipotent thiazolidide 9. Extensive SAR studies on the phenyl ring of 9 led to the discovery of a novel series of potent and selective DP-IV inhibitors. Introduction of a fluorine at the 2-position proved to be crucial for the potency of this series. The 2,5-difluoro (22q) and 2,4,5-trifluoro (22t) analogues were potent inhibitors of DP-IV (IC50=270, 119nM, respectively). (C) 2004 Elsevier Ltd. All rights reserved.