1-[3-(2,4-Dichloro-5-fluoro-phen-yl)-5-(3-methyl-2-thien-yl)-4,5-dihydro-1H-pyrazol-1-yl]ethanone.

In the title mol-ecule, C(16)H(13)Cl(2)FN(2)OS, the dihedral angle between the thio-phene and benzene rings is 80.34 (12)°. The pyrazoline ring is in an envelope conformation, and the plane through the four coplanar atoms makes dihedral angles of 85.13 (9) and 6.89 (10)° with the thio-phene and benzene rings, respectively. The C and O atoms of the acetyl group are nearly coplanar with the attached pyrazoline ring. In the crystal structure, inversion dimers arise from pairs of inter-molecular C-H⋯O hydrogen bonds. A short inter-molecular Cl⋯S contact of 3.4250 (13) Å is also found.