{4-Hydroxy-3-[4-nitro-2-(2,2,2-trifluoro-ethylsulfanylmethyl)-phenoxy]-phenyl}-acetic acid methyl ester (0.40 g, 0.92 mmol), sodium chlorodifluoroacetate (0.282 g, 1.86 mmol), and potassium carbonate (0.14 g, 1.02 mmol) were combined in DMF:H2O (8.5:1; 4.6 mL) and degassed with N2 for 15 minutes. The reaction was then stirred at 100° C. for 4 hours. After work-up with EtOAc and 1N aqueous HCl, the residue was purified by silica gel chromatography to give {4-difluoromethoxy-3-[4-nitro-2-(2,2,2-trifluoro-ethylsulfanylmethyl)-phenoxy]-phenyl}-acetic acid methyl ester.
