Vijesh, A.M.Isloor, A.M.Isloor, S.Shivananda, K.N.Shyma, P.C.Arulmoli, T.2020-03-312020-03-312011Der Pharma Chemica, 2011, Vol.3, 4, pp.454-463https://idr.nitk.ac.in/handle/123456789/13278Invasive microbial infections are major problems around the world, especially in immuno compromised patients. The recent expansion of antimicrobial drug research has occurred because there is a critical need for new antimicrobial agents to treat these life threatening invasive infections. In the present study three series of new substituted pyrazolone derivatives (5a-f, 6a-f and 8a,b) were synthesized by the Knoevenagel condensation reaction of pyrazolones (3a,b) with various substituted carbaldehydes (4a-f, 7). These newly synthesized compounds were characterized by IR, NMR, mass spectra and also by C, H, N analyses. New compounds were screened for their antimicrobial studies against S. aureus, B. subtilis, E. coli and P. aeruginosa. The results revealed that compounds 5c and 6c having 2,5-dichlorothiophene substituent showed significant antibacterial activity against all tested microorganisms as compared to the standard drug Ceftriaxone.Article