title: 2-Chloro-8,8-dimethyl-8,9-dihydro-7H-chromeno[2,3-b]quinoline-10,12-dione.
abstract: The asymmetric unit of the title compound, C(18)H(14)ClNO(3), contains two independent mol-ecules (A and B). In both mol-ecules, the cyclo-hexa-none ring has a chair conformation. The dihedral angles between the pyran ring and the pyridine and chloro-phenyl rings are 2.13 (9) and 2.19 (9)°, respectively, in A, and 0.82 (9) and 1.93 (9)°, respectively, in B. The carbonyl O atoms deviate from the pyran and benzene rings to which they are attached by -0.092 (2) and 0.064 (2) Å, respectively, in A, and by -0.080 (2) and -0.063 (2) Å, respectively, in B. In the crystal, the A mol-ecules are linked via C-H⋯O hydrogen bonds, forming double-stranded chains along [100]. They lie parallel to the double-stranded chains formed by the B mol-ecules, which are also linked via C-H⋯O hydrogen bonds. The chains stack up the c axis in an -A-A-B-B-A-A- manner, with a number of π-π inter-actions involving A and B mol-ecules; the centroid-centroid distances vary from 3.4862 (11) to 3.6848 (11) Å
authors: Centre of Advanced Study in Crystallography and Biophysics, University of Madras, Guindy Campus, Chennai 600 025,  India.
authors: Thothadri
authors: T
authors: Srinivasan
authors: Panneerselvam
authors: P
authors: Yuvaraj
authors: Boreddy S R
authors: BS
authors: Reddy
authors: Devadasan
authors: D
authors: Velmurugan