Diethyl 7,7′-di­chloro-4-oxo-4H-[1,4′-bi­quinoline]-3,3′-di­carboxyl­ate

In the title compound, C(24)H(18)Cl(2)N(2)O(5), the quinoline and quinolinone moieties are nearly perpendicular to each other, forming a dihedral angle of 82.36 (3)°. In the crystal, mol­ecules form a halogen bond between a Cl atom of a quinolinone moiety and the N atom of the quinoline moiety of the inversion equivalent [Cl⋯N = 3.106 (3) Å]. The mol­ecules also form two kinds of C—H⋯O hydrogen-bonded centrosymmetric inversion dimers, making chains along the c-axis direction which are further inter­linked by the halogen bonds into layers parallel to the bc plane.