Microwave assisted synthesis and structure-activity relationship of 4-hydroxy-N′-[1-phenylethylidene]-2H/2-methyl-1,2-benzothiazine-3-carbohydrazide 1,1-dioxides as anti-microbial agents

► 4-Hydroxy-N′-[1-phenylethylidene]-2H/2-methyl, 1,2-benzothiazine-3-carbohydrazide 1,1-dioxides. ► 1,4-Dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide. ► 4-Methyl-1,4-dihydropyrazolo[4,3-c][1,2]benzothiazin-3-ol 5,5-dioxide. ► Anti-fungal and anti-bacterial assay. ► Microwave assisted synthesis.