The vitronectin receptor αvβ3 has been identified as a promising potential target for the treatment of osteoporosis, diabetic retinopathy and cancer. We have recently reported 5- substituted indoles 3-[5-[2-(5, 6, 7, 8-tetrahydro [1, 8] naphthyridin-2-yl) ethoxy] indol-1-yl]-3- (3-pyridyl) propionic acid 3 and 3-[5-[2-(5, 6, 7, 8-tetrahydro [1, 8] naphthyridin-2-yl) ethoxy] indol-1-yl]-3-(3, 4-methylenedioxyphenyl) propionic acid 4, as an original series of potent ...