反应详情

To a stirred mixture of compound F4 (451 mg, 2.00 mmol) in acetic acid (6 mL) at room temperature was added a solution of sodium cyanate (169 mg, 2.60 mmol) in water (2.5 mL) dropwise over 2 min. After addition, the reaction mixture was stirred for another 2 h and then concentrated under reduced pressure. The resulting residue was mixed with saturated aqueous sodium bicarbonate (50 mL) and extracted with methylene chloride (3×150 mL). The combined organic extracts were dried over anhydrous sodium sulfate, filtered, and concentrated under reduced pressure. The resulting residue was purified by flash column chromatography on silica gel eluting with methanol/methylene chloride (15:85) to afford compound M1 as a yellow solid (125 mg, 23%): 1H NMR (300 MHz, DMSO-d6) δ 10.45 (s, 1H), 7.31 (bs, 1H), 6.77 (bs, 3H), 3.41 (s, 2H), 2.73 (d, J=4.8 Hz, 2H), 2.63 (d, J=4.8 Hz, 2H), 2.50-2.45 (m, 2H), 1.06 (t, J=7.0 Hz, 3H). MS (M+H) 269.

1. additionAfter addition
2. concentrationconcentrated under reduced pressure
3. additionThe resulting residue was mixed with saturated aqueous sodium bicarbonate (50 mL)
4. extractionextracted with methylene chloride (3×150 mL)
5. dry with materialThe combined organic extracts were dried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customThe resulting residue was purified by flash column chromatography on silica gel eluting with methanol/methylene chloride (15:85)