Ethyl 5-{[(E)-2-(isonicotinoyl)hydrazinyl­idene]methyl}-3,4-dimethyl-1H-pyrrole-2-carboxyl­ate dihydrate

In the title compound, C(16)H(18)N(4)O(3)·2H(2)O, the dihedral angle between the pyrrole and pyridine rings in the hydrazone mol­ecule is 7.12 (3)°. In the crystal structure, inter­molecular N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds link the hydrazone and water mol­ecules into double layers parallel to (101). The crystal packing exhibits weak π–π inter­actions between the pyrrole and pyridine rings of neighbouring hydrazone mol­ecules [centroid–centroid distance = 3.777 (3) Å]. The crystal studied was a non-merohedral twin, the refined ratio of twin domains being 0.73 (3):0.27 (3).