X-ray mapping in heterocyclic design: V. Diffractometric study of the crystal structure of 2-hydroxy-3-trifluoracetylimidazo[1,2-a]pyridine hydrochloride at 180 K

The crystal structure of 2-hydroxy-3-trifluoracetylimidazo[1,2-a]pyridine hydrochloride C₉H₆F₃ClN₂O₂ is determined by X-ray diffraction at 180 K. The structure is solved by the direct method and refined by the least-squares procedure to R = 0.0296. The alternation of bond lengths in the six-membered fragment of the molecule is observed. One of the specific features of the crystal structure is the formation of a system of the N-H?Cl^? (N?Cl, 3.09 Å; N-H, 0.83 Å; H?Cl, 2.33 Å; and N-H?Cl, 153°) and O-H?Cl^? (O?Cl, 2.87 Å; O-H, 0.95 Å; H?Cl, 1.92 Å; and O-H?Cl, 178°) hydrogen bonds in which the chlorine atoms are related to the reference atom by different symmetry transformations.