反应详情

2N KOH(aq) was added to a solution of 18.3 (304 mg, 0.65 mmol) in ethanol (5 mL). The reaction was stirred at room temperature overnight and then taken up in copious water. The aqueous solution was adjusted to pH=2.0 with 1N HCl(aq) and extracted with ethyl acetate (2×25 mL). The combined organic layers were washed with water, followed by brine. The solvent was removed under reduced pressure and the resulting residue was purified via radial chromatography (40% ethyl acetate in Hexanes+0.1% AcOH) to yield 150 mg (52%) of compound 18 as a glass. LC/MSD m/e: 444.0 (M+H); 1H NMR (400 MHz) (acetone) δ 8.21 (2H, m), 7.89 (2H, d, J=8.0 Hz), 7.38 (2H, m), 7.03 (2H, m), 5.06 (2H, s), 4.06 (1H, m), 2.70 (2H, m), 2.52 (3H, s), 1.81 (3H, s).

1. extractionextracted with ethyl acetate (2×25 mL)
2. washThe combined organic layers were washed with water
3. customThe solvent was removed under reduced pressure
4. customthe resulting residue was purified via radial chromatography (40% ethyl acetate in Hexanes+0.1% AcOH)