Synthesis and "in vitro" cardiovascular activity of 4-aryl-2,3,3a,4-tetrahydro-1h-pyrrolo[2,1-c][1,4]benzothiazin-1-ones and 7-acetoxy-6-phenyl-7a,8,9,10-tetrahydropyrrolo [2,1,-d][1,5]benzothiazepin-10-one

The synthesis and the pharmacological characterization of novel heterocyclic systems 1 and 2 is described. On radioreceptor assay 1a showed higher affinity for Calcium Channel Receptors (CCRs) and in functional studies higher potency and efficacy as negative inotropic agent than Diltiazem, without relevant calcium antagonist activity on vascular smooth muscle, revealing a clear-cut selectivity for cardiac over vascular tissue. © 1994.