Pyridine → 5-Bromo-3,4-difluoro-2-(4-iodo-2-methyl-phenylamino)-benzoic acid pentafluorophenyl ester

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Reaction Steps

To a solution of 5-Bromo-3,4-difluoro-2-(4-iodo-2-methyl-phenylamino)-benzoic acid (prepared as described in WO 99/01426) (1.61 g, 3.4 mmol) and pyridine (0.31 mL, 3.83 mmol) in anhydrous dimethylformamide (7 mL) was added pentafluorophenyl trifluoroacetate (0.71 mL, 4.13 mmol). The resultant solution was stirred at ambient temperature for 18 h. The reaction mixture was diluted with ether (100 mL) and washed with water (40 mL), 0.1 M aqueous hydrochloric acid (40 mL), saturated aqueous sodium bicarbonate (40 mL), and saturated brine (40 mL). The organics were dried over anhydrous magnesium sulfate and concentrated under reduced pressure to afford a foam that was purified on silica gel. Elution with hexanes-ethyl acetate (19:1) afforded 5-Bromo-3,4-difluoro-2-(4-iodo-2-methyl-phenylamino)-benzoic acid pentafluorophenyl ester (1.95 g, 89%) as a pale-yellow powder: 1H NMR (400 MHz, CDCl3) δ 8.59 (s, 1 H), 8.24 (d, J=5.8 Hz, 1 H), 7.54 (s, 1 H), 7.45 (d, J=8.4 Hz, 1 H), 6.70 (dd, J=8.4, 5.3 Hz, 1 H), 2.26 (s, 3 H).

Provenance & Evidence