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

Abstract

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.

Keywords:

• cyclocondensation reaction
• spirothiazolidinones
• cycloaddition reaction
• antibacterial activity
• antifungal activity

Acknowledgements

The authors are thankful to Head, Department of Chemistry, Kakatiya University, Warangal, India, for the facilities and to Director, Indian Institute of Chemical Technology, Hyderabad, India, for the spectral facility.