Author: R.Sharma, M. Sapnakumari, B. Narayana, B.K.Sarojini, R. Kant

DOI:

The title compound 1-[5-(4-Bromophenyl)-3-(4-Fluorophenyl)-4, 5-dihydro-1H-Pyrazol-1-yl]-2-Chloropropan-1-one (2) was synthesized by reacting chalcone, (2E)-3-(4-Bromophenyl)-1-(4-Fluorophenyl) prop-2-en-1-one (1) with hydrazine hydrate in the presence of 2-chloro propionic acid. It has been crystallizes using ethanol by using slow evaporation process in the orthorhombic space group P2₁2₁2₁ with unit cell parameters a = 8.1984(9), b = 11.1417(22), c = 19.2217(10) Å, α=β=ϒ=90.00(0)º. The molecule is essentially planar except thepyrazoline ring which is slightly deviated and adopts normal envelope conformation. The methyl group attached to pyrazoline ring through the carbon atoms C10 and C11 is disordered over two positions C12/C12A with site occupancy ratio of 50:50. The crystal structure features the presence of inter-molecular [C-H…F] and intra-molecular [C-H…N] hydrogen bonds, as well as π-π interactions [between the Pyrazoline ring and Fluorophenyl ring], which contributes to the stabilization of the crystal structure.The structure of the compound is characterized by elemental analysis, ¹H NMR spectra and Single crystal XRD.

Keywords: 2-Pyrazoline, Crystal Structure, Direct Method, Intermolecular interaction, Confirmation.