Synthesis, crystal structures and DFT studies of 1-[2-(5-methyl-2-benzoxazolinone-3-yl)acetyl]-3-phenyl-5-(3,4-dimethoxyphenyl)-4,5-dihydro-1H-pyrazole and 1-[2-(5-chloro-2-benzoxazolinone-3-yl)acetyl]-3-phenyl-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole

The title compounds, 1-[2-(5-methyl-2-benzoxazolinone-3-yl)acetyl]-3-phenyl-5-(3,4-dimethoxyphenyl)-4,5-dihydro-1H-pyrazole (5a) and 1-[2-(5-chloro-2-benzoxazolinone-3-yl)acetyl]-3-phenyl-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazole (5b), were synthesized. The crystal and molecular structures of 5a and 5b have been determined by elemental analyses, IR, 1H NMR, ESI-MS and single-crystal X-ray diffraction. Molecular geometries of 5a and 5b in the ground state have been calculated using the density functional method (DFT) with B3LYP/6-31G(d,p) basis set and compared with the experimental data. In addition, the molecular electrostatic potential maps and frontier molecular orbitals of 5a and 5b were performed.

► We report the synthesis of two new 2-pyrazolines. ► These compounds were structurally characterized by spectroscopic and X-ray measurements. ► Molecular geometries have been calculated using the density functional method and compared with the experimental data.