In one aspect, the invention provides compounds of Formula I Formula Ia, Formula Ib, Formula Ic, and Formula Id and salts, hydrates and isomers thereof. In another aspect, the invention provides a method of promoting
bone formation in a subject in need thereof by administering to the subject a therapeutically effective amount of a compound of Formula I, Formula Ia, Formula Ib, Formula Ic, or Formula Id. The present invention also provides orthopedic and periodontal devices, as well as methods for the treatment of renal
disease, diabetes bone loss, and
cancer, using a compound of Formula I, Formula Ia, Formula Ib, Formula Ic, or Formula Id.