反应详情

A suspension of the product of Example 352C (100 mg, 0.352 mmol) in glacial acetic acid (3 mL) was treated at room temperature with a solution of concentrated nitric acid in glacial acetic acid (1.43 M, 0.305 mL, 0.436 mmol) and stirred at this temperature for 19 hours. Added additional 1.43 M nitric acid/acetic acid (0.020 mL, 0.029 mmol) and let stir for 1.5 hours. The reaction was diluted with water (30 mL) and extracted with ethyl acetate (2×50 mL). The combined organic extracts were washed with brine, dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The residue was purified by column chromatography on silica gel eluting with 8% methanol/dichloromethane to give the title compound as a light yellow solid (47 mg, 41%). MS (ESI−) m/z 328 (M−H)−. 1H NMR (300 MHz, PYRIDINE-d5) δ 0.98 (t, J=7.17 Hz, 3 H) 3.86 (s, 2 H) 4.01 (q, J=7.23 Hz, 2 H) 7.11 (d, J=8.82 Hz, 1 H) 7.22 (d, J=8.82 Hz, 1 H).

1. stirringlet stir for 1.5 hours
2. extractionextracted with ethyl acetate (2×50 mL)
3. washThe combined organic extracts were washed with brine
4. dry with materialdried over anhydrous sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified by column chromatography on silica gel eluting with 8% methanol/dichloromethane