title: tert-Butyl 4-{[5-(4-chloro-phen-yl)-1-(4-fluoro-phen-yl)-1H-pyrazol-3-yl]carbon-yl}piperazine-1-carboxyl-ate.
abstract: In the title pyrazole derivative, C(25)H(26)ClFN(4)O(3), both benzene rings are twisted out of the plane through the pyrazole ring, with dihedral angles of 67.62 (10) and 27.63 (10)° for the fluoro- and chloro-substituted rings, respectively. The dihedral angle between the two benzene rings is 64.54 (9)°. The piperazine ring (with a chair conformation) is linked to the pyrazole ring via a carbonyl spacer and is orientated to lie to one side of the pyrazole plane. In addition to an intra-molecular C-H⋯N contact, there are inter-molecular C-H⋯O inter-actions, which generate a supra-molecular chain with an undulating topology along the c axis that is sustained by alternating centrosymmetric ten-membered {⋯HCNCO}(2) and {⋯HC3O}(2) synthons.
authors.forename: R Venkat
authors.initials: RV
authors.lastname: Ragavan
authors.forename: V
authors.initials: V
authors.lastname: Vijayakumar
authors.forename: S
authors.initials: S
authors.lastname: Sarveswari
authors.forename: Seik Weng
authors.initials: SW
authors.lastname: Ng
authors.forename: Edward R T
authors.initials: ER
authors.lastname: Tiekink