Crystal and molecular structures of two thiopyranylidenedihydropyridine SS-dioxides

Abstract

The crystal and molecular structures of 1,2-dihydro-1-methyl-2-(5-phenylthiopyran-2-ylidene)pyridine SS-dioxide (1) and 1,4-dihydro-1-methyl-4-(2-methyl-5-phenylthiopyran-4-ylidene)pyridine SS-dioxide chloroform solvate (2) have been determined from X-ray three-dimensional diffraction data. Both structures have been solved by direct methods and refined by block-diagonal least-squares to R 5·4 [(1); 2512 reflections] and 7·8%[(2); 2259 reflections]. Crystals are monoclinic space group P2₁/c, Z= 4; (1): a= 8·56(1), b= 7·46(1), c= 22·50(1)Å, β= 96·1 (2)°; (2): a= 11·58(1), b= 16·13(1), c= 10·82(1)Å, β= 91·2(2)°. The results suggest, that particularly in (2), the sulphur atom of the thiopyran ring participates in π delocalisation.