Dichloromethane → 2-Amino-4-fluoro-5-iodobenzoic acid

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Reaction Steps

To a vigorously stirred solution of dichloromethane (700 ml), methanol (320 ml), and 2-amino-4-fluoro-benzoic acid (33.35 grams, 215 mmoles) was added solid sodium hydrogencarbonate (110 grams, 1.31 moles) followed by portion addition of benzyltrimethyl ammonium dichloroiodate (82.5 grams, 237 mmoles). The mixture was allowed to stir for 48 hours. The mixture was filtered to remove the insolubles. The remaining solid residue was washed with 200 ml of dichloromethane. The filtrate was concentrated and redissolved in a one to one mixture of ethyl acetate (1 litre) and a 0.2 N solution of sodium hydroxide (1 litre), added to a 2 litre separatory funnel and extracted. The organic layer was washed with an additional 200 ml of water. The aqueous layers were combined and acidified with 2N hydrochloric acid. The resulting precipitate was collected by suction filtration, washed with water and dried under vacuum at 60° C. to yield 46.5 grams (77%) of the title compound. 1H NMR (400 MHz, DMSO-d6) δ: 8.04(d, 1H), 7.1(s, broad, 2H), 6.63(d, 1H). ESI-MS m/z 280 (M−1).

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