• Archives of Pharmacal Research
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• v.12 no.2
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• pp.135-137
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• 1989

A convenient route is reported for the synthesis of certain series of 4H-thieno[2,3-b][1]benzothiopyran-4-ones, carrying various substituents at position 2 such as arylazomethines (7,8), thiazolidin-4-ones (9-13), ${\alpha},\;{\beta}-unsaturated$ ketones (16,17), 2-pyridones (19-23), tetrahydrothiophen-4-ones (24,28), and nitroalkenes (29,30), as potential schistosomicidal or antihistaminic agents.

• Archives of Pharmacal Research
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• v.13 no.1
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• pp.24-27
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• 1990

Reaction of 2-formyl-4H-thieno [2, 3-b] benzothiopyran-4-one (1) with different heterocyclic amines afforded the corresponding Schiff's bases (2-4). Diethyl malonate, ethyl cyanoacetate and malononitrile were reached with 1 to afford compounds 5, 7 and 8, respectively. Compound 5 was cyclized to the pyrazolidin-3, 4-dione (6) by the action of hydrazine hydrate, whereas compound 7 was utilized for the synthesis of the thiazolin-4 one derivatives (9-13).