Synthesis, Characterization and Evaluation of Biological Activity of New Spirocyclic Pyrazolones

Vipin Kumar Singh Vijay Pratap Singh, Amrendra Kumar Singh

Abstract: Stereoselective Michael- aldol sequential reaction is used for synthesis of carbocyclic six membered spiro Pyrazolones. The [(Z)-4-bromo-3-(4-chlorophenyl)but-2-enal] and [(E)-4-benzylidene-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazole-3-one] were stirred in DCM in 20-mol % of catalyst (lb) and 20-mol % of O- fluoro benzoic acid, gives [(5S)-8-(4-chlorophenyl)-4-methyl-2, 10-diphenyl-2, 3-diazaspiro(4- 5)deca-3, 7-diene-1, 6-dione], with high range of diastereoselectivity and enantioselectivity (up to >20:1 dr and 99% ee ). The synthesized compound gives satisfactory results for 1H NMR, 13C NMR, IR spectra, and polarimeter. Antimicrobial by examinations shows all newly synthesized derivatives are active against bacteria (S. aureus, B. subtilis, P. aeruginosa and E. coli), and Fungi (A. niger).

Keywords: Stereoselective, ?-? unsaturated aldehyde, vinyl Pyrazolones, Antimicrobial agent, Carbocyclic