Studies on bi-heterocyclic compounds. I. 6-Substituted dihydro-1,4-thiazinones.

Abstract

Reactions of 5-methyl-2H-1, 4-thiazin-3 (4H) -one (4) with various N-acylpyridinium salts (7a-g) led to (N-acyldihydropyridyl) thiazinones (5a-g), oxidation of which yielded a new class of pyridylthiazinones (6a-g). These reactions were applied to the synthesis of other azaarylthiazinones. Some of these azaarylthiazinones, particularly 6- (4-pyridyl) thiazinones (6a, 14a and 14b) showed positive inotropic activity with little chronotropic effect on guinea pig left atria.