Synthesis of some new 10H-pyrido(3,2-b)(1,4)benzothiazine and their ribofuranosides as possible chemotherapeutic agents

N-(2',3',5'-tri-O-benzoyl-β-D-ribofuranosyl)-8-chloro-7-methyl/7,9-dimethyl/8-chloro-9-methyl-3-nitro pyrido[3,2-b][1,4]benzothiazine have been synthesized by the treatment of 10H-8-chloro-7-methyl/ 7,9-dimethyl/8-chloro-9-methyl-3-nitropyrido[3,2-b][1,4]benzothiazines-with β-D-ribofuranose-1-acetate-2,3,5-tribenzoate in toluene. Compounds 10Η-8-chloro-7-methyl/7,9-dimethyl/8-chloro-9-methyl-3-nitro pyrido[3,2-6][1,4]benzothiazine and 10-acetyl-8-chloro-7-methyl/7,9-dimethyl/ 8-chloro-9-methyl-3-nitro pyrido[3,2-b][1,4]benzothiazine-5-oxide have been synthesized. The structure of all the synthesized compounds have been established by elemental analysis, IR and 1 H NMR spectral data. All the synthesized heterocyclic compounds and their ribofuranosides have been screened for their antibacterial and antifungal activity.