Synthesis and biological activity of 5-heteroaryl benzodiazepines: analogues of YM022

A novel series of analogues of the potent gastrin/CCK-B receptor antagonist YM022 have been prepared which incorporate 5- and 6-membered heteroaromatic rings in the benzodiazepine 5-position. The 5-(2-pyridyl) derivatives in particular retained good in vitro and in vivo potency and one such compound 9i was shown to inhibit acid secretion after oral dosing in dogs. Improved bioavailability for 9i over the 5-phenyl analogue, 9h was demonstrated in rats.