Synthesis, spectral studies and antimicrobial activities of some 2-naphthyl pyrazoline derivatives

Article abstract of DOI:10.1016/j.saa.2012.04.082

A series of 2-naphthyl pyrazolines were synthesized by the cyclization of 2-naphthyl chalcones and phenylhydrazine hydrochloride in the presence of sodium acetate. The yields of pyrazoline derivatives are more than 80%. The synthesized pyrazolines were characterized by their physical constants, IR, ¹H, ¹³C and MS spectra. From the IR and NMR spectra the CN (cm^-1) stretches, the pyrazoline ring proton chemical shifts (ppm) of δH_a, H_b and H_c and also the carbon chemical shifts (ppm) of δCN are correlated with Hammett substituent constants, F and R, and Swain-Lupton's parameters using single and multi-regression analyses. From the results of linear regression analysis, the effect of substituents on the group frequencies has been predicted. The antimicrobial activities of all synthesized pyrazolines have been studied.