Crystal structure of febuxostat-acetic acid (1/1)

The asymmetric unit of the title compound [systematic name: 2-(3-cyano-4-isobutylo xypheny1)-4-methylthiazole-5-carboxylic acid-acetic acid (1/1)1, C16H16NO3 center dot S center dot CH3COOH contains a febuxostat molecule and an acetic acid molecule. In the febuxostat molecule, the thiazole ring is nearly coplanar with the benzene ring [dihedral angle = 3.24 (2) I. In the crystal, the febuxostat and acetic acid molecules are linked by O-H center dot center dot center dot O, O-H center dot center dot center dot N hydrogen bonds and weak C-H center dot center dot center dot O hydrogen bonds, forming supramolecular chains propagating along the b-axis direction. pi-pi stacking is observed between nearly parallel thiazole and benzene rings of adjacent molecules; the centroid-to-centroid distances are 3.8064 (17) and 3.9296 (17) angstrom.