Sodium Hydroxide → 5-Cyano-4-fluoro-2-methoxy-benzoic acid

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Reaction Steps

A stirring suspension of 5-cyano-4-fluoro-2-methoxy-benzoic acid methyl ester (2.98 g, 14.25 mmol) in ethanol (30 mL, 0.5 M) was treated with 1.25 M NaOH (68 mL, 85.5 mmol). Within 10 minutes, the solution was clear and by TLC, all of the starting material was consumed. The solution was concentrated and then treated with 2N HCl until the pH was 1. The white precipitate formed was collected by suction filtration, dissolved in dioxane, and was washed with aq saturated NaCl. The organic layer was dried over Na2SO4, filtered and concentrated to afford 5-cyano-4-fluoro-2-methoxy-benzoic acid (1.9 g, 70%) as a white solid. Rf=0.34 (20% methanol in dichloromethane); 1H NMR (CDCl3, 300 MHz) δ 8.13 (d, J=8.1 Hz, 1H), 7.36 (d, J=12.0 Hz, 1H), 3.90 (s, 3H).

Provenance & Evidence