Spirocyclic nonpeptide glycoprotein IIb–IIIa antagonists. Part 2: design of potent antagonists containing the 3-azaspiro[5.5]undec-9-yl template

The synthesis and biological activity of novel glycoprotein IIb–IIIa anatagonists containing 3-azaspiro[5.5]undec-9-yl nucleus are described. The potent activity of these compounds as platelet aggregation inhibitors demonstrates the utility of the monoazaspirocyclic structure as central template for nonpeptide RGD mimics.