Efficient procedures for the preparation of 1,4-benzothiazine-based bicyclic and tricyclic heterocycles have been developed. The reaction of 2-[(cyanomethyl)sulfanyl]phenyl isothiocyanate, readily prepared from commercially available 2-aminobenzenethiol, with sodium hydride was found to give, after aqueous workup, 3-thioxo-3,4-dihydro-2H-1,4-benzothiazine-2-carbonitrile. Treatment with alkyl halides prior to workup yielded 3-(alkylsulfanyl)-4H-1,4-benzothiazine-2-carbonitriles. Successive treatment of these compounds with sodium hydride and alkyl halides afforded 4-alkyl-3-(alkylsulfany1)-2H-1,4-benzothiazine-2-carbonitriles. These procedures can be applied to the synthesis of some 1,4-benzothiazine-based tricyclic heterocycles.