Date Published: May 01, 2009
Publisher: International Union of Crystallography
Author(s): Hoong-Kun Fun, Samuel Robinson Jebas, M. Babu, B. Kalluraya.
The asymmetric unit of the title compound, C20H18F2N2O2S, contains four independent molecules, two of which are paired into a dimer by way of two N—H⋯S hydrogen bonds. The other two independent molecules are paired into two centrosymmetric dimers via pairs of intermolecular N—H⋯S hydrogen bonds. In one molecule, the carboxylate O atoms, methylene and methyl groups attached to the benzene ring are disordered between two positions in a 0.908 (3):0.092 (3) ratio. In two of the independent molecules, the F and H atoms of the diflourophenyl ring are flip-flop disordered (i.e. by 180° about the C—C bond axis linking the ring to the rest of the molecule) in a 3:2 ratio. The crystal packing is stabilized by weak intermolecular C—H⋯O hydrogen bonds.
For details of the synthesis, see: Kalluraya & Rai (2003 ▶); Kappe (1993 ▶); Steele et al. (1998 ▶). For the pharmaceutical applications of pyrimidine derivatives, see: Atwal (1990 ▶); Manjula et al. (2004 ▶); Sadanandam et al. (1992 ▶). For bond-length data, see: Allen et al. (1987 ▶). For ring puckering analysis, see: Cremer & Pople (1975 ▶). For stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶).