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|a A new series of 3-alkylthio-6-chlorothieno[2,3-e]-1,4,2-dithiazine-1,1-dioxides (51a-e) was prepared using a new synthetic approach. This has been established by the reaction of carbon disulfide with 2,5-dichloro thiophene-3-sulphonamide which in first place was afforded by deprotonation using sodium hydride as a base, followed by alkylation of the intermediate 3-thione-2,3-dihydro-6-chlorothieno[2,3-e]-1,4,2-dithiazine-1,1-dioxide sodium salt (50) with alkyl halides. Desulfonation of 3-methylthio-6-chlorothieno[2,3-e]-1,4,2-dithiazine-1,1-dioxides (51a) with sulfuryl chloride to produce 3,6-dichlorothieno[2,3-e]-1,4,2-dithiazine-1,1-dioxide (52), which was used as a potential starting reagent for the synthesis of 3-alkylthio and 3-arylamino-6-chlorothieno[2,3-e]-1,4,2-dithiazine-1,1-dioxide (53a,b), represents a new approach for the synthesis of similar derivatives. In addition, the derivatives, 2-alkyl-3-(substitutedimino)-2,3-dihydro-6-chlorothieno[2,3-e]-1,4,2-dithiazine-1,1-dioxide (55a, 51b), were also prepared via the reaction of N-alkyl-2,5-dichlorothiophene-3-sulfoneamide (54a-c) with sodium hydride and the appropriate isothiocyanate derivatives in good yields. The structures of all new bicyclic derivatives were suggested based on microanalytical analysis together with MS and NMR spectroscopy. Biological evaluation of the new compounds shows no significant activity against both gram positive bacteria (E.coli) and gram negative (S.aureus).
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