Ethyl Acetate → 7-fluoro-2,2-dimethyl-3,4-dihydro-2H-chromene-4-carboxylic acid

참여 물질

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반응 단계

To 7-fluoro-2,2-dimethyl-2,3-dihydrochromen-4-one (1.000 g, 5.149 mmol) was added trimethylsilyl cyanide (3.215 mL, 25.75 mmol) followed by a spatula tip of zinc iodide. The reaction was heated at 50° C. for 1 hour. The reaction was cooled, diluted with ethyl acetate (40 mL) and washed with saturated sodium bicarbonate (2×25 mL), brine (25 mL), dried over magnesium sulfate and concentrated. The product was dissolved in 5 mL of acetic acid and 5 mL of HCl, and SnCl2 dihydrate (4.648 g, 20.60 mmol) was added. The reaction heated at reflux (130° C. oil bath temperature) overnight. The reaction was cooled, diluted with ethyl acetate (50 mL), washed with water (50 mL) and brine (50 mL), dried over magnesium sulfate and concentrated. The residue was purified by silica gel chromatography over silica gel eluting with a gradient of 0.5% MeOH/CH2Cl2 containing 0.5% acetic acid to 10% MeOH/CH2Cl2 containing 0.5% acetic acid to provide the title compound (0.280 g, 24.25% yield).

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