Abstract
A convenient synthesis of a series of new N-benzylidene-N-(1-ethyl-2, 2-dioxo-2,3-dihydro-lambda H-2 lambda(6)-benzo[c][1,2]thiazin-4-ylidene)-hydrazines is reported. The starting compound methyl anthranilate was reacted with methane sulfonyl chloride, followed by N-ethylation and cyclization reactions. This cyclized 2,1-benzothiazine 2.2-dioxide molecule was then subjected for hydrazinolysis with hydrazine followed by condensation reactions with a number of aromatic aldehydes yielding the 2,1-benzothiazine 2,2-dioxide hydrazine. Structural elucidation was achieved by FT-IR, H-1 and C-13 NMR and single crystal X-ray diffraction analyses. Crystal structure data for 6a has been given with a brief structural discussion. The newly synthesized compounds were then screened for their antioxidant activity by ABTS radical cation decolourization assay and metal chelating activity.