Simple and Efficient One-Pot Synthesis, Spectroscopic Characterization and Crystal Structure of Methyl 5-(4-Chlorobenzoyloxy)-1-phenyl-1H-pyrazole-3-carboxylate

A facile one-pot synthesis of methyl 5-(4-chlorobenzoyloxy)-1-phenyl-1H-pyrazole-3-carboxylate (4) is described. The title compound was efficiently synthesized by the reaction of phenyl hydrazine, dimethyl acetylenedicarboxylate and 4-chlorobenzoyl chloride in dichloromethane under reflux in good yield. The structure of the target compound was deduced by modern spectroscopic and analytical techniques and unequivocally confirmed by a single crystal X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P 21 21 21 with cell parameters a = 6.6491(3) Å, b = 7.9627(6) Å, c = 30.621(5) Å, α = β = γ = 90° and Z = 4. The crystal packing of the compound (4) is stabilized by an offset π-stacking between the planar benzoyl-substituted diazole moieties.