ChemInform Abstract: Synthesis and Analgesic Activity of Novel Heterocycles, (1)Benzothiopyrano(3,4-b)pyrrole Derivatives.
Abstract
Wittig-Horner olefination of the ketone (I) with the phosphonate (II) gives the unsaturated ester (III) which is cyclized, forming the benzothiopyranylacetic acid (IV) as the major product.
ChemInform Abstract
Wittig-Horner olefination of the ketone (I) with the phosphonate (II) gives the unsaturated ester (III) which is cyclized, forming the benzothiopyranylacetic acid (IV) as the major product. Amidation of (IV) by a mixed anhydride method and subsequent reduction produce the amine (VII). Acylation of (VII) with ethyl chlorocarbonate (VIII) followed by oxidation yields the sulfoxide (IX). This is cyclized via an intermediate α-halo sulfoxide, forming the cis-fused heterocycle (X) as a mixture of diastereomers. The phenol derivative (XI) obtained from (X) shows analgetic activity. (X-Ray data of one diastereomer of (X): monoclinic, space group P21, Z=2).
