反应详情

A 250-mL round-bottomed flask equipped with a magnetic stirrer was charged with 117b (2.44 g, 5.91 mmol), methanol (80 mL), 50% hydroxylamine in water (390 mg, 11.8 mmol) and the reaction was stirred at room temperature for 4 h. After this time, the reaction mixture was concentrated, and the resulting residue was purified by column chromatography to afford an 86% yield (1.27 g) of 117c as a yellow solid: mp 103-104° C.; 1H NMR (500 MHz, CDCl3) δ 7.94 (d, 1H, J=2.0 Hz), 7.49 (dd, 1H, J=8.5, 2.5 Hz), 6.53 (d, 1H, J=8.5 Hz), 4.48 (br s, 2H), 4.30 (t, 2H, J=8.5 Hz), 3.88 (dd, 2H, J=8.5, 4.5 Hz), 3.62 (m, 1H), 1.44 (s, 9H); MS (ESI+) m/z 249.9 (M+H).

1. customA 250-mL round-bottomed flask equipped with a magnetic stirrer
2. concentrationAfter this time, the reaction mixture was concentrated
3. customthe resulting residue was purified by column chromatography