反应详情

An oven dried flask was charged with 4-fluoro-2-nitrobenzoic acid (7.87 g, 42.5 mmol), 1-hydroxybenzotriazole (6.32 g, 46.8 mmol), 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide (8.96 g, 46.7 mmol) and ethyl acetate (150 mL), followed by fast dropwise addition of triethylamine (11.8 mL, 84.7 mmol) at room temperature. The resulting white suspension was stirred for 3 h. The reaction was poured into 1:1 water/ethyl acetate (400 mL). After separation, the aqueous layer was extracted with ethyl acetate (200 mL). The combined organic layer was washed with brine (50 mL), dried over magnesium sulfate, and concentrated in vacuo to give a solid upon standing over night. Trituration and washing with ethyl acetate (2×6 mL) afforded the title compound as a light yellow solid (9.87 g, 71% yield). 1H-NMR (CDCl3, 400 MHz) δ 7.74 (dd, J=6.4, 2.0, 1H), 7.50 (dd, J=6.8, 4.0, 1H), 7.43-7.22 (m, 6H), 5.71 (d, J=6.4, 1H), 4.05-3.93 (m, 1H), 3.50 (s, 2H), 2.85-2.79 (m, 2H), 2.20-2.14 (m, 2H), 2.05-2.02 (m, 2H), 1.58-1.49 (m, 2H). Mass spec.: 358.49 (MH+).

1. customAn oven dried flask
2. customAfter separation
3. extractionthe aqueous layer was extracted with ethyl acetate (200 mL)
4. washThe combined organic layer was washed with brine (50 mL)
5. dry with materialdried over magnesium sulfate
6. concentrationconcentrated in vacuo
7. customto give a solid
8. waitupon standing over night
9. washTrituration and washing with ethyl acetate (2×6 mL)