A series of compounds structurally relate to 4'-[(2, 3, 4, 5-tetrahydro-1H-1-benzazepin-1-yl)carbonyl]benzanilide was synthesized and demonstrated to have arginine vasopressin (AVP) antagonist activity for both V_1A and V₂ receptors. The introduction of a phenyl or a 4-substituted phenyl group into the ortho position of the benzoyl moiety resulted in an increase in both binding affinity and antagonistic activity. The 2-(4-methylphenyl) derivative (1g) exhibited high antagonistic activities for both V_1A (8.6-fold) and V₂ (38-fold) receptors and high oral activity (8.6-fold) compared with the 2-methyl lead compound (1a). Datail of the synthesis and the pharmacological properties of this series are presented.