Synthesis and Biological Evaluation of 1,2,4-Triazolo[2,3-a]pyrrole Derivatives as Alpha-4 ( α4) Integrin Antagonists

In exploring for templates to devise novel antagonists for the integrins α4β1 and α4β7, was a series of compounds identified possessing a 1,2,4-triazolo[2,3-a]pyrrole structural subunit. Compound 11, for example, was found to antagonize α4β1-VCAM-1 and α4β7-MAdCAM-1 adhesion with IC50 values of 80 and 20 nM, respectively.