Refinement of the Structure of Alclofenac, 4-Allyloxy-3-Chlorophenyl acetic acid ($C_{11}H_{11}O_{3}CI$)

The structure of alclofenac was determined by single crystal X-ray diffraction analysis. The compound was recrystallized from chloroform solution in monoclinic system space group $C_{2}$/c, with Z = 8, a = 8, a = 23.349(9), b =14.295 (3), c = 7.192 (2) $\AA$, $\beta$ = 111.32 (3)$^{\circ}$, and $d_{dbs}$ = 1.29, $d_{caic}$ = 1.30. The structure was solved by direct method and refined by least-squares procedure to the final R-value being 0.044 for 1055 reflections (F ${\geq}6${\sigma}$(F)). The molecules are dimerized by OH..O type hydrogen bonds related by two-fold axis.