Ultrasound and microwave assisted rapid and sustainable route to synthesis of benzothiazine derivatives

Ultrasound and microwave assisted synthesis of 2-Meldrum-2H,4H-2-carbonyl methyl-3-oxo-1,4-benzothiazine 10, 2-dimidone-2H,4H-2-carbonyl methyl-3-oxo-1,4-benzothiazine 11, 2H,4H-2-amino-[3-methyl pyrazol-5-one-1-yl]-carbonyl methyl-3-oxo-1,4-benzothiazine 12,2H,4H-2-amino-[3,5-dmethyl pyrazol-1-yl]-carbonyl methyl-3-oxo-1,4-benzothiazine 13 and 2H, 4H-2-amino-[3-phenyl, 5-methyl pyrazol-1-yl]-carbonyl methyl-3-oxo-1,4-benzothiazine 14 from 2-aminobenzenethiol and 1,3 diketo compounds containing active methylene group have been carried out. All the synthesized compounds have been investigated for their antibacterial activities. The result indicate that the compounds show convincing activities against Gram-positive bacteria (Bacillus subtilis and Streptococcus lads) when compared with standard drug (ampicillin trihydrate). These compounds have been also synthesized by conventional method and their structures have been elucidated on the basis of spectral analyses and chemical reactions.