We have identified a novel series of tricyclic pyrazinobenzodiazepines, represented by general structure 2, as potent vasopressin receptor antagonists. For example, 3 binds with high affinity to human V2 receptors and is very selective relative to V1a receptors. Compound (R)-(+)-3 exhibited pronounced aquaretic activity in rats and dogs on oral administration.
Keywords: g-protein-coupled receptors, smooth muscle contraction, glycogen, corticotropin, oxazinobenzodiazepines, hydrophobicity, secondary amine, crystallization, oxygen systems