Firoz Pasha Shaik

Design, synthesis, antibacterial and antifungal activity of novel spiro-isoxazolyl bis-[5,5′]thiazolidin-4-ones and spiro-isoxazolyl thiazolidin-4-one-[5,5′]-1,2-4 oxdiazolines

The synthesis of novel isoxazolyl 1,6-dithia-4,9-diazaspiro[4.4]nonane-3,8-diones (4a–h) and isoxazolyl 1-oxa-6-thia-2,4,9-triazaspiro[4.4]non-2-ene-8-ones (5a–h) analogs is described. Reaction of N-1-\{3-methyl-5-[(E)-2-aryl-1-ethenyl]-4-isoxazolyl}-2-chloroacetamide (2) with aryl isothiocyanates yielded 3,3-methyl-5-[(E)-2-aryl-1-ethenyl]-4-isoxazolyl-2-(arylimino)-1,3-thiazolan-4-ones (3). Cyclocondensation of 3 with mercaptoacetic acid furnished novel isoxazolyl-1,6-dithia-4,9-diazaspiro[4.4]nonane-3,8-diones (4a–h). Cycloaddition of 3 with benzonitrile oxides afforded novel isoxazolyl 1-oxa-6-thia-2,4,9-triazaspiro[4.4]non-2-ene-8-ones (5a–h). Compounds 4a–h and 5a–h showed significant biological activity against all the standard strains.

Synthesis of 3-[4-({Methyl-5-[(E)-2-phenyl-1-ethenyl]-4-isoxazolyl}amino)-1,3-thiazol-2-yl]-2-aryl-1,3-thiazolan-4-ones as Potential Biodynamic Agents

A series of isoxazolyl thiazolyl thiazolidinones ( 4a–h ) were synthesized starting from isoxazolyl chloroacetamide 1 . Compound 1 upon heating with thiourea in ethanol furnished N4-{3-methyl-5-[(E)-2-phenyl-1-ethenyl]-4-isoxazolyl]-1,3-thiazole-2,4-diamine 2 . Condensation of 2 with aromatic aldehydes afforded corresponding Schiff bases ( 3a–h ), which undergo cyclocondensation on treatment with mercaptoacetic acid to give 3-[4-({methyl-5-(E)-2-phenyl-1-ethenyl]-4-isoxazolyl] amino)-1,3-thiazol-2-yl]-2-aryl-1, 3-thiazolyl –4-ones ( 4a–h ) in excellent yields. Structures of all the synthesized compounds have been established by elemental analyses, IR, 1H NMR, and mass spectral data.