2-Heteroaryl 2-substituted phenylketone derivatives and their inhibitory activity on platelet aggregation

R 68070 and CV-4151 are two compounds possessing both thromboxane synthetase inhibitory activity and thromboxane receptor antagonist properties. 2-Heteroaryl 2-substituted phenylketone derivatives with a partial structural similarity to R 68070 and CV-4151, i.e. possessing a phenyl and a heteroaryl moiety, have been prepared and found to have antiplatelet activity. The compound 2-thienyl 2'-hydroxyphenyl ketone (4) was shown to completely inhibit platelet aggregation induced by arachidonic acid at a concentration of 5.0 microM. Structure-activity analysis indicated that the presence of a ketone group is an important requirement for this inhibitory activity. An o-hydroxyl substitution on the phenyl ring, and a 2-thienyl of heteroaryl ring might increase inhibitory activity.