2,7-Bis(trichloromethyl)-1,8-naphthyridine

The complete molecule of the title compound, C10H4Cl6N2, is generated by crystallographic twofold symmetry, with two C atoms lying on the rotation axis; the 1,8-naphthyridine ring is almost planar with an r.m.s. deviation of 0.0002 Å. In the crystal structure, the molecules are stacked in an antiparallel manner along [001]. Short Cl⋯Cl [3.3502 (4)] and Cl⋯N [3.2004 (11)–3.2220 (10) Å] contacts are observed in the crystal structure.

The complete molecule of the title compound, C 10 H 4 Cl 6 N 2 , is generated by crystallographic twofold symmetry, with two C atoms lying on the rotation axis; the 1,8-naphthyridine ring is almost planar with an r.m.s. deviation of 0.0002 Å . In the crystal structure, the molecules are stacked in an antiparallel manner along [001]. Short ClÁ Á ÁCl [3.3502 (4)] and ClÁ Á ÁN

Comment
The substituted 1,8-naphthyridine compounds have been studied for their chemical and biological activities for a long time.
They show various biological activities such as antibacterial (Chen et al., 2001;Ferrarini et al., 1998), anti-inflammatory (Braccio et al., 2008) as well as antihypertensive (Ferrarini et al., 2000) properties. Trichloromethyl-substituted heterocyclic compounds are of great importance due to their broad spectrum biological activities. These interesting properties prompt us to synthesise the title compound (I) and its crystal structure was reported.
The asymmetric unit of the title molecule ( Fig. 1), C 10 H 4 Cl 6 N 2 , contains one half-molecule with two shared C atoms (C3 and C4) lying on a twofold rotation axis. The 1,8-naphthyridine ring is planar with the r.m.s. deviation of 0.0002 (2) Å.
In the crystal structure (Fig. 2), the non-covalent interactions play a significant role in the three-dimensional supramolecu- All these interactions connect the molecules into a three-dimensional supramolecular network.

Experimental
A mixture of N-chlorosuccinimide (500 mg, 4.5 mmol) and triphenylphosphine (500 mg, 4.2 mmol) was moistened with CCl 4 (60 ml) in a round bottom flask and stirred at room temperature for 25 min. A solution of 2,7-dimethyl-1,8-naphthyridine (0.9 g, 5.25 mmol) was added to the suspension and the reaction mixture was stirred and heated under reflux for 7 hr. The solution was cooled and filtered. The evaporated filtrate was washed with saturated aqueous Na 2 CO 3 and extracted repeatedly with CHCl 3 . Drying over anhydrous Na 2 SO 4 , the solvent was removed under reduced pressure. The crude product was purified with SiO 2 chromatography (eluted with 1% ethylacetate in petroleum ether) to give the title compound as a white crystalline solid. Colorless slabs of (I) were recrystalized from CH 2 Cl 2 :hexane (1:10, v/v) by the slow evaporation of the solvent at room temperature after a week.
supplementary materials sup-2 Refinement H atoms were located in a difference maps and refined isotropically. The highest residual electron density peak is located at 1.72 Å from H6 and the deepest hole is located at 0.65 Å from Cl2. Fig. 1. The molecular structure of (I) showing 50% probability displacement ellipsoids. Atoms with suffix A were generated by symmetry code -x, y, -1/2 -z.

Special details
Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 120.0 (1) K.
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance mat- Geometric parameters (Å, °)