Hydrogen-bonding and C-H...pi interactions in ethyl 4-acetyl-5-methyl-3-phenyl-1H-pyrrole-2-carboxylate monohydrate.

In the title compound, C(16)H(17)NO(3).H(2)O, the pyrrole ring is distorted slightly from ideal C(2v) symmetry. Three strong hydrogen bonds link the substituted pyrrole and water molecules to form infinite chains, in which the hydrogen bonds form rings and chain patterns. Two intermolecular C-H.pi interactions maintain the internal cohesion between these chains. The molecular structure differs slightly from that of the isolated molecule calculated by ab initio quantum-mechanical calculations. In the latter model, the non-H substituent atoms share the plane of the pyrrole ring, except for the phenyl group, which lies almost perpendicular to this plane.