Synthesis, antiinflammatory, and cytotoxic activity of novel pyrazolo[4,3‐c][2,1]benzothiazine 4,4‐dioxide derivatives

13 novel pyrazolo[4,3-c][2,1]benzothiazine 4,4-dioxide derivatives that mimic the pharmacophore of piroxicam as well as celecoxib were conveniently synthesized in a catalyst-free and atom-economical method in which an unconventional redox-neutral reaction of 2-nitrochalcones with elemental sulfur to straightforward access to 2,1-benzothiazine 2,2-dioxide core is the key step. Eight new pyrazolo[4,3-c][2,1]benzothiazine derivatives significantly inhibited NO production than the positive control. Besides that, most of the compounds exhibited weak cytotoxic activity suggesting a potent and selective antiinflammatory activity related to the antiproliferative activity of these novel compounds. Thus, incorporation of the pharmacophoric groups of the two above drugs in a single molecule plays an important role in determining a better antiinflammatory activity of the new compounds.