Imidazopyridines as VLA-4 integrin antagonists.

We describe a novel series of imidazopyridine substituted phenylalanines which are potent VLA-4 antagonists. A wide variety of substituents are tolerated as replacements for the pendant 3-pyridyl ring. A clear structure-activity relationship was identified around the substitution of the 3-amino-cyclobut-2-enone portion of the molecule.