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

Abstract

The asymmetric unit of the title compound [systematic name: 2-(3-cyano-4-isobutyloxyphenyl)-4-methylthiazole-5-carboxylic acid–acetic acid (1/1)], C16H16N2O3S·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)°]. In the crystal, the febuxostat and acetic acid molecules are linked by O—H...O, O—H...N hydrogen bonds and weak C—H...O hydrogen bonds, forming supramolecular chains propagating along the b-axis direction. π–π 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) Å.

Keywords

• crystal structure
• febuxostat
• acetic acid
• co-crystal
• hydrogen bonding
• π–π stacking