The design and synthesis of novel integrin alpha(V)beta(3) antagonists based on a 1,5- or 2,5-substituted tetrahydrobenzaezpinone core is described. In vitro activity of respective compounds was determined via alpha(V)beta(3) binding assay, and selected derivatives were submitted to further characterization in functional cellular assays. SAR was obtained by modification of the benzazepinone core, variation of the spacer linking guanidine moiety and core, and modification of the guanidine mimetic. These efforts led to the identification of novel alpha(V)beta(3) inhibitors displaying potency in the subnanomolar range, selectivity versus alpha(IIb)beta(3) and functional efficacy in relevant cellular assays. A method for the preparation of enantiomerically pure derivatives was developed, and respective enantiomers evaluated in vitro. Compounds 31 and 37 were assessed for metabolic stability, resorption in the Caco-2 assay and pharmacokinetics.