反应详情

A solution of methyl 3-cyclopropoxy-2-nitrobenzoate (4.7 g, 19.81 mmol) in THF (30 mL) and MeOH (30 mL) was treated with a solution of lithium hydroxide (2.88 g, 120 mmol) in water (15 mL, 833 mmol). The mixture was stirred at room temperature for 2 hours. The organic solvents were removed under reduced pressure. The resulting aqueous slurry was diluted with water, acidified with 1M HCl and extracted with ethyl acetate (3×). The extracts were combined and washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated to provide 3-cyclopropoxy-2-nitrobenzoic acid (4.35 g, 19.8 mmol, 98% yield) as a yellowish solid. HPLC: RT=2.186 min (H2O/MeOH with TFA, SunFire C18 3.5 μm, 2.1×30 mm, gradient=4 min, wavelength=220 nm); MS(ES):m/z=246 [M+Na]+; 1H NMR (400 MHz, chloroform-d) δ 7.76 (dd, J=7.7, 1.8 Hz, 1H), 7.68-7.46 (m, 2H), 4.02 (tt, J=6.0, 2.9 Hz, 1H), 1.00-0.52 (m, 4H).

1. customThe organic solvents were removed under reduced pressure
2. additionThe resulting aqueous slurry was diluted with water
3. extractionextracted with ethyl acetate (3×)
4. washwashed with brine
5. dry with materialdried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated