2-Pyridylimidazoles as inhibitors of xanthine oxidase

Abstract
A series of 24 4-substituted and 4,5-disubstituted 2-pyridylimidazoles was synthesized and evaluated in vitro for inhibition of xanthine oxidase [bovine]. Included within this group are examples of 2-pyridylimidazopyridines and halosubstituted 2-pyridylbenzimidazoles. Five compounds exhibited inhibitory activity in the same range as the standards, 4-hydroxypyrazolo [3,4-d]pyrimidine and 2-(4-pyridyl)-4-trifluoromethylimidazole. Two examples, 2-(4-pyridyl)-4,5-dicyanoimidazole and 2-(4-pyridyl)-4-nitroimidazole, were at least an order of magnitude more active than the standards and therefore rank among the most potent known inhibitors of the enzyme.