Abstract
A series of new Coumarin linked pyrazoline derivatives were synthesized by condensation of 3-Acetylcoumarin with substituted aryl benzaldehydes in chloroform in the presence of piperidine which resulted in intermediate compounds (D1-D10; 3-aryl substituted-1-(3-coumarinyl) propen-1-one`s). These chalcones upon cyclisation with 2, 4-Dinitrophenylhydrazine(2,4-DNP) yielded desired target compounds (E1-E10; 1, 5-disubstituted-3-(4,5-dihydro-1h-pyrazol-3yl)-2h-chromen-2-one) with the yield in the range of 28-55%. All the synthesized compounds were characterized by 1HNMR. The synthesized compounds were screened for anti bacterial activity against bacterial strains viz. Bacillus subtilis, Bacillus Cereus, Escherichia coli Klebsiella pneumonia. All the compounds were found to posses moderate to good activity, out of all the synthesized compounds (E3) i.e 3-(5-(4-(dimethylamino) phenyl)-1-(2, 4-dinitrophenyl)-4,5-dihydro-1H –pyrazol-3-yl)-2H-chromen-2-one was screened with highest activity.
