Synthesis and biological evaluation of some novel pyrazolines

Abstract

A novel series of pyrazolines were synthesized from 2-thiophene carboxaldehyde (I). in ethanol with substituted acetophenones (II) in presence of NaOH yielded corresponding 2- substituted -3-thiophene-2-yl-prop-2-en-1-one (III) which on treatment with hydrazine hydrate in presence of catalytic amount of piperidine yielded 2-substituted-3-thiophene-2-yl-4,5-dihydro-1H-1 pyrazole(IV). The structures of the final synthesized compounds (IVa-IVi) were established on the basis of IR, H- NMR, MASS spectral data. The synthesized compounds were screened for antibacterial and antifungal activities. When compared to the antifungal activity, compounds showed very good antibacterial activity.