Novel heterocyclic analogues of the new potent class of calcium entry blockers: 1-[[4-(aminoalkoxy)phenyl]sulfonyl]indolizines.

Several heterocyclic analogues of the potent 1-[[4-(aminoalkoxy)phenyl]sulfonyl]indolizines were synthesized and evaluated for their antagonistic calcium activities in comparison with the 1-sulfonylindolizine SR 33557 and the usual calcium antagonist references verapamil, cis-(+)-diltiazem, and nifedipine. The bicyclic nine-membered rings were, in general, more potent than the bicyclic 10-membered or five-membered rings. Among the bicyclic nine-membered rings, the indole nucleus appeared to be extremely favorable to support the calcium antagonistic activity.

A novel class of calcium-entry blockers: the 1[[4-(aminoalkoxy)phenyl]sulfonyl]indolizines.

The synthesis and initial biological evaluation of a series of 1-sulfonylindolizines is described. These compounds have been shown to be representatives of a novel class of potent, slow-channel calcium antagonists. All compounds were found to be at least as active as the reference calcium antagonists verapamil and cis-(+)-diltiazem.