A monoclinic polymorph of 4-(2H-1,3-benzodioxol-5-yl)-1-(4-methylphenyl)-1H-pyrazol-5-amine

• Main Authors: Mukesh M. Jotani, Nilesh N. Gajera, Mukesh C. Patel, Herman H. Y. Sung, Edward R. T. Tiekink
• Format: Article
• Language: English
• Published: International Union of Crystallography 2015-10-01
• Series: Acta Crystallographica Section E: Crystallographic Communications
• Subjects: crystal structure; amine; polymorph; conformation; Hirshfeld surface
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S2056989015016023

The title compound, C17H15N3O2, is a monoclinic polymorph (P21/c with Z′ = 1) of the previously reported triclinic (P-1 with Z′ = 2) form [Gajera et al. (2013). Acta Cryst. E69, o736–o737]. The molecule in the monoclinic polymorph features a central pyrazolyl ring with an N-bound p-tolyl group and a C-bound 1,3-benzodioxolyl fused-ring system on either side of the C atom bearing the amino group. The dihedral angles between the central ring and the N- and C-bound rings are 50.06 (5) and 27.27 (5)°, respectively. The angle between the pendent rings is 77.31 (4)°, indicating the molecule has a twisted conformation. The five-membered dioxolyl ring has an envelope conformation with the methylene C atom being the flap. The relative disposition of the amino and dioxolyl substituents is syn. One of the independent molecules in the triclinic form has a similar syn disposition but the other has an anti arrangement of these substituents. In the crystal structure of the monoclinic form, molecules assemble into supramolecular helical chains via amino–pyrazolyl N—H...N hydrogen bonds. These are linked into layers via C—H...π interactions, and layers stack along the a axis with no specific interactions between them.