4-Methyl-5-phenyl-1H-pyrazol-3(2H)-one.

ABSTRACT: The asymmetric unit of the title compound, C(10)H(10)N(2)O, contains two crystallographically independent mol-ecules with similar geometries, which exist in the keto form. The C=O bond lengths are 1.2878?(12)?Å in mol-ecule A and 1.2890?(12)?Å in mol-ecule B, indicating that the compound undergoes enol-to-keto tautomerism during the crystallization process. In mol-ecule A, the pyrazole ring is approximately planar [maximum deviation = 0.007?(1)?Å] and forms a dihedral angle of 36.67?(6)° with the attached phenyl ring. In mol-ecule B, the dihedral angle formed between the pyrazole ring [maximum deviation = 0.017?(1)?Å] and the phenyl ring is 41.19?(6)°. In the crystal, inter-molecular N-H?O hydrogen bonds link neighbouring mol-ecules into dimers generating R(2) (2)(8) ring motifs. These dimers are linked into ribbons along [101] via inter-molecular N-H?O hydrogen bonds, forming R(4) (2)(10) ring motifs.

SUBMITTER: Loh WS 

PROVIDER: S-EPMC3050219 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature