2-Oxochromen-4-yl 4-(dimethylamino)benzoate

In the title molecule, C18H15NO4, the benzoate ring is oriented at a dihedral angle of 43.43 (6)° with respect to the planar [maximum deviation = 0.038 (2) Å] chromene ring. The crystal structure features R 2 2(12) centrosymetric dimers formed via C—H⋯O interactions and these dimeric aggregates are connected by C—H⋯π interactions.

In the title molecule, C 18 H 15 NO 4 , the benzoate ring is oriented at a dihedral angle of 43.43 (6) with respect to the planar [maximum deviation = 0.038 (2) Å ] chromene ring. The crystal structure features R 2 2 (12) centrosymetric dimers formed via C-HÁ Á ÁO interactions and these dimeric aggregates are connected by C-HÁ Á Á interactions.
Cg3 is the centroid of the C15-C18/C22/C23 ring. Coumarin constitutes one of the major classes of naturally occurring compounds, and interest in its chemistry continues unabated because of its usefulness as biologically active agents. It also represents the core structure of several molecules of pharmaceutical importance. Coumarin and its derivatives have been reported to serve as anti-bacterial (Ukhov et al., 2001;Abd Elhafez et al., 2003;Basanagouda et al., 2009;Liu et al., 2008), anti-oxidant (Trapkov et al., 1996Vukovic et al., 2010), anti-inflammatory (Emmanuel-Giota et al., 2001;Hamdi & Dixneuf, 2007), anti-coagulant (Hamdi et al., 2007) and anti-tumour (Wang et al., 2001Marchenko et al., 2006) agents. Therefore, the synthesis of new coumarin derivatives is of considerable interest. In order to study the influence of new substituents on the activity of the coumarin derivative, the title compound, (I), has been synthesized and in this paper, we present its molecular structure, Fig. 1.

Experimental
To a solution of 4.10 -2 mole of paradimethylamino benzoyl chloride in 150 ml of dried tetrahydrofuran, was added 0.12 mole of dried triethylamine and 4.10 -2 mole of 4-hydroxycoumarin by small portions over 30 min. The mixture was then refluxed for 3 h and poured in 300 ml of chloroform or dichloromethane. The solution was acidified with dilute hydrochloric acid until the pH was 2 or 3. The organic layer was extracted, washed with water, dried over MgSO 4 and the solvent removed.
The crude product was recrystallized in chloroform. Colourless crystals of the title compound are obtained in a good yield: 82.6%; M.pt. 445 K.

Refinement
The H-atoms were placed at calculated positions and were included in the refinement in the riding model approximation with C-H in the range of 0.94-0.99 Å, and with U iso (H) = 1.2-1.5U eq (C).