A second monoclinic polymorph of 4-(2-hydr-oxy-4-methoxy-benzyl-ideneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one.

ABSTRACT: The title compound, C(19)H(19)N(3)O(3), prepared by condensing 4-amino-anti-pyrine and 4-meth-oxy-2-hydroxy-benzaldehyde in methanol, is the second monoclinic polymorph of this compound which crystallizes in the space group C2/c. The structure was previously reported [Wang, Zhang, Yan, Zheng & Yang (2007 ?). Acta Cryst. E63, o1245-o1246] in the space group P2(1)/c. The hydroxyl group is disordered over two positions with occupancies of 0.787?(4) and 0.213?(4). The triply substituted benzene ring and the phenyl ring form dihedral angles of 12.2?(2) and 53.7?(2)°, respectively, with the pyrazolone ring; the corresponding values in the P2(1)/c polymorph are 7.5?(2) and 42.6?(2)°. Intra-molecular O-H?N and C-H?O hydrogen bonds are observed in the major disorder component. Adjacent molecules are linked through intermolecular O-H?O hydrogen bonds, forming dimers.

SUBMITTER: Zhu ZF 

PROVIDER: S-EPMC2959388 | biostudies-other | 2008 Sep

REPOSITORIES: biostudies-other