Ethyl 8-meth­oxy-4-oxo-1,4-di­hydro­quinoline-3-carboxyl­ate

In the title compound, C(13)H(13)NO(4), the asymmetric unit contains four independent mol­ecules, each exhibiting an intra­molecular N—H⋯O hydrogen bond. The ethyl group in one of the four mol­ecules is disordered, with a refined occupancy ratio of 0.295 (16):0.705 (16). A face-to-face stacking inter­action is found between the benzene rings of the quinoline units of two of the mol­ecules [centroid–centroid distance = 3.541 (2) Å], which are sandwiched by the other two mol­ecules through N—H⋯O hydrogen bonding. In the crystal, the sandwiched mol­ecules are assembled via stacking inter­actions along the b-axis direction with their translation-symmetry equivalents [centroid–centroid distance = 3.529 (2) Å], and are further linked through N—H⋯O hydrogen bonding. The other two mol­ecules are linked via stacking inter­actions with their inversion-symmetry equivalents [centroid–centroid distances = 3.512 (3) and 3.716 (4) Å] and via N—H⋯O hydrogen bonding.