反应详情

A 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer was charged with glyoxylic acid (618 mg, 6.72 mmol), toluene (20 mL), N,N-isopropylmethylamine (486 mg, 6.60 mmol) and 4-(tert-butoxycarbonylamino) phenylboronic acid (1.58 g, 6.66 mmol). The reaction was sealed with a plastic cap under a nitrogen atmosphere and stirred at room temperature for 7 d. After this time, the reaction was concentrated under reduced pressure. The resulting residue was subjected to flash chromatography to afford 25 in 62% yield (1.34 g) as a light brown solid: mp 320° C. dec, 1H NMR (300 MHz, DMSO-d6) δ 9.42 (s, 1H), 7.42 (d, 2H, J=8.7 Hz), 7.37 (d, 2H, J=8.7 Hz), 4.23 (s, 1H), 3.28 (m, 1H), 3.17 (s, 1H), 2.23 (s, 3H), 1.47 (s, 9H), 1.15 (d, 3H, f=6.6 Hz), 1.11 (d, 3H, J=6.6 Hz); MS (ESI+) m/z 323 (M+H).

1. customA 50-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. customThe reaction was sealed with
3. customa plastic cap under a nitrogen atmosphere
4. concentrationAfter this time, the reaction was concentrated under reduced pressure