反应详情

A 10-mL single-neck round-bottomed flask equipped with a magnetic stirrer, and nitrogen inlet was charged with 2-methoxy-5-(2-methyl-3-nitrophenyl)pyridine (8) (1.00 g, 4.10 mmol) and pyridine hydrochloride (1.90 g, 16.4 mmol) and purged with nitrogen. The flask was place for five min into an oil bath preheated to 165° C. After this time the reaction was cooled to room temperature, and water (70 mL) was added. The resulting suspension was filtered, and the filter cake was washed with water (2×25 mL) and then dried in a 43° C. vacuum oven for 3 h to afford 0.97 g (99%) of 5-(2-methyl-3-nitrophenyl)pyridin-2-one (9) as a white solid: mp 214-216° C.; 1H NMR (300 MHz, DMSO-d6) 11.87 (br s, 1H), 7.85 (dd, 1H, J=8.1, 1.2 Hz), 7.56 (dd, 1H, J=7.8, 1.5 Hz), 7.54 (dd, 1H, J=8.4, 2.4 Hz), 7.53 (d, 1H, J=9.3 Hz), 7.46 (dd, 1H, J=7.8, 1.5 Hz), 6.41 (d, 1H, J=9.3 Hz), 2.30 (s, 3H); MS (ESI+) m/z 231 (M+H).

1. customA 10-mL single-neck round-bottomed flask equipped with a magnetic stirrer, and nitrogen inlet
2. custompurged with nitrogen
3. customfor five min
4. custompreheated to 165° C
5. additionwater (70 mL) was added
6. filtrationThe resulting suspension was filtered
7. washthe filter cake was washed with water (2×25 mL)
8. customdried in a 43° C. vacuum oven for 3 h