INVESTIGATION INTO THE REGIOCHEMISTRY OF SOME PYRAZOLES DERIVED FROM 1,3-DIPOLAR CYCLOADDITION OF ACRYLONITRILE WITH SOME NITRILIMINES: THEORETICAL AND EXPERIMENTAL STUDIES

1,3-dipolar cycloaddition between acrylonitrile and two N-(4-substituted)phenyl-C-(4-chlorophenyl)nitrilimines which were generated in situ afforded the new pyrazoles. The regiochemistry and reactivity of these reactions has been investigated on the basis of density functional theory (DFT)-based reactivity indexes and activation energy calculations. The theoretical C-13 NMR. chemical shifts of the cycloadducts which were obtained by GIAO method were comparable with the observed values.