THEORETICAL AND EXPERIMENTAL STUDY ON THE REGIOSELECTIVITY OF ACRYLONITRILE AND METHYLMETHACRYLATE 1,3-DIPOLAR CYCLOADDITION TO SOME NITRILIMINES.

1,3-dipolar cycloaddition between acrylonitrile and methylmethacrylate with two N-(4-bromophenyl)-C-(4-substituted) nitrilimines which were generated in situ afforded the new pyrazoles. The regioselectivity 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 13C NMR chemical shifts of the cycloadducts which were obtained by GIAO method were comparable with the observed values. [ABSTRACT FROM AUTHOR]