Acta Cryst. (2009). E65, o275-o276  [ doi:10.1107/S1600536809000488 ]

Ethyl 5-amino-1-(4-chloro-2-nitrophenyl)-1H-pyrazole-4-carboxylate

M. Zia-ur-Rehman, M. R. J. Elsegood, J. A. Choudary, M. Fasih Ullah and H. L. Siddiqui

Abstract: In the molecule of the title compound, C₁₂H₁₁ClN₄O₄, the pyrazole ring is coplanar with the amino and ethoxycarbonyl groups within 0.026 (2) and 0.105 (2) Å, respectively. The C₆ ring of the 4-chloro-2-nitrophenyl group is twisted by 53.58 (4)° relative to the plane of the pyrazole ring. The planar structure of the pyrazole ring is stabilized by an intramolecular N-HO hydrogen bond between its substituents. Neighbouring molecules are linked through intermolecular N-HN and N-HO hydrogen bonds, giving rise to one-dimensional tapes along the b axis. Molecules in the chain are linked to those of an adjacent chain through weak C-HO interactions, forming a three-dimensional network.

Online 10 January 2009

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