(Z)-Ethyl 4-chloro-2-[(4-chlorophenyl)hydrazono]-3-oxobutanoate

The title compound, C12H12Cl2N2O3, crystallizes as a non-merohedral twin with a twinning ratio of 0.51:0.49. The molecule adopts a keto–hydrazo tautomeric form stabilized by an intramolecular N—H...O hydrogen bond. The configuration around the N—N bond is trans.