Methanol → 3-[(2S)-1-(Difluoromethoxy)propan-2-yl]oxy-5-[5-(dimethylcarbamoyl)pyrazin-2-yl]oxy-benzoic acid

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Reaction Steps

Methyl 3-[(2S)-1-(difluoromethoxy)propan-2-yl]oxy-5-[5-(dimethylcarbamoyl)pyrazin-2-yl]oxy-benzoate (19.8 g, 46.6 mmol) was dissolved in THF (300 mL) and methanol (100 mL) and LiOH (1N, 51.3 mL) was added followed by water dropwise till it went cloudy. The resultant solution was stirred for 16 hours at room temperature. The organics were removed by evaporation under reduced pressure. The aqueous slurry was diluted with water (100 mL), washed with ethyl acetate (200 mL), then acidified by addition of hydrochloric acid (2N) until a solid precipitated. The resulting suspension was extracted with ethyl acetate (2×200 mL). The combined organic extracts were washed with water (200 mL) and brine (200 mL), dried (MgSO4), filtered and concentrated under reduced pressure to afford the product (17.2 g, 90%). 1H NMR δ (CDCl3): 1.39 (d, 3H), 3.17 (s, 3H), 3.19 (s, 3H), 3.93-4.05 (m, 2H), 4.60-4.69 (m, 1H), 6.26 (t, 1H), 6.99 (t, 1H), 7.50-7.55 (m, 2H), 8.38 (d, 1H), 8.55 (d, 1H), 10.17 (s, 1H); m/z 412 (M+H)+

Provenance & Evidence