(2S,4S)-1-[2-(1,1-dimethyl-3-oxo-3-pyrrolidin-1-yl-propylamino)acetyl]-4-fluoro-pyrrolidine-2-carbonitrile: a potent, selective, and orally bioavailable dipeptide-derived inhibitor of dipeptidyl peptidase IV.

Abstract A series of 2-[3-[2-[(2 S )-2-cyano-1-pyrrolidinyl]-2-oxoethylamino]-3-methyl-1-oxobutyl]-based DPP-IV inhibitors with various monocyclic amines were synthesized. The structure–activity relationships (SAR) led to the discovery of potent DPP-IV inhibitors, having IC 50 values of 50  > 20 μM). Of these compounds, the analogues 12a , 12h and 12i exhibited a long-lasting ex vivo DPP-IV inhibition in rats.