A series of 5,7-diphenyl-3-ureidohexahydroazepin-2-one cholecystokinin
-B (CCK-B) receptor antagonists was synthesized using Beckmann ring ex
pansion of a suitable 2,4-diphenylcyclohexanone as a key step. SAR stu
dies revealed the importance of the 5-aryl group for high and selectiv
e CCK-B receptor affinity, as illustrated in compound(-)10i (CCK-B IC5
0 = 6.8 nM).