反应详情

The product of Example 14 (2.2 g, 10 mmol) was dissolved in dichloromethane (10 ml), oxalyl chloride (2.6 ml, 30 mmol) was added dropwise, and the reaction was carried out at room temperature for 1 hr, then the reaction solution was concentrated to give a pale yellow oil which was thereafter dissolved in dichloromethane, and then the resulted solution was added dropwise to an ice bath cooled solution of dimethylamine hydrochloride (1.6 g, 20 mmol) and triethylamine (4.3 ml, 30 mmol) in dichloromethane. Then it was slowly warmed to room temperature to make the reaction carry out for 1 hour. The pH was adjusted to about 7 with 1N hydrochloric acid, then the reaction solution was extracted with dichloromethane, and the organic phases were combined, washed with saturated sodium bicarbonate solution and saturated brine, dried over anhydrous sodium sulfate concentrated, and recrystallized with petroleum ether and ethyl acetate to give a white solid 2.3 g, yield: 92%. 1HNMR (300 MHz, CDCl3): δ 7.2 (1H, t, J=7.9, 15.6), 6.6-6.8 (3H, m), 3.7 (3H, s), 2.8-2.9 (1H, m), 2.7-2.8 (1H, m), 2.6 (3H, s), 2.5 (3H, s), 1.7-1.8 (1H, m), 1.4-1.6 (1H, m), 1.1 (3H, d, J=6.2), 0.8 (3H, t, J=6.8, 14.3). ESI-MS: 250.4 (M+H).

1. concentrationthe reaction solution was concentrated
2. customto give a pale yellow oil which
3. additionthe resulted solution was added dropwise to an ice bath
4. waitcarry out for 1 hour
5. extractionthe reaction solution was extracted with dichloromethane
6. washwashed with saturated sodium bicarbonate solution and saturated brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated
9. customrecrystallized with petroleum ether and ethyl acetate