Studies on Dihydropyridines. III. Synthesis of 4, 7-Dihydrothieno [2, 3-b]-pyridines with Vasodilator and Antihypertensive Activities

Abstract

A series of 4-aryl-4, 7-dihydrothieno [2, 3-b] pyridine-5-carboxylate derivatives (I) was synthesized and tested for binding affinity to Ca²⁺ channels in rat cerebral cortex membranes, coronary vasodilator effect in isolated guinea pig hearts, and antihypertensive activity in spontaneously hypertensive rats.Several compounds had potent coronary vasodilator and antihypertensive activities.The structure-ctivity relationships of the series indicated that a lipophilic 3-alkyl substituent with moderate bulkiness was effective for enhancing the pharmacological potencies.Among them, methyl 4, 7-dihydro-3-isobuty1-6-methy1-4-(3-nitrophenyl) thieno [2, 3-b] pyridine-5-carboxylate (S-312) was selected as a promising cardiovascular agent.The relationship between the absolute configuration of S-312 and its biological activities is also presented.