反应详情

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer, reflux condenser and nitrogen inlet was charged with THF (15 mL), 3,5-dibromo-1-methylpyrazin-2(1H)-one (1.00 g, 3.73 mmol), 3-aminopyridine (351 mg, 3.73 mmol) and sodium tert-butoxide (789 mg, 8.21 mmol). After bubbling nitrogen through the resulting solution for 30 min, Pd2Br2(t-Bu3P)2 (29 mg, 0.037 mmol) was added, and the reaction mixture was stirred at room temperature for 2.5 h. After this time the reaction was partitioned between ethyl acetate (50 mL) and water (50 mL) and filtered. The aqueous layer was separated and extracted with ethyl acetate (2×25 mL). The organic layers were combined, washed with brine (50 mL) and dried over sodium sulfate. The drying agent was removed by filtration and the filtrate concentrated under reduced pressure. The resulting residue was purified by column chromatography to afford a 35% yield (370 mg) of 112a as a brown solid: mp>250° C.; 1H NMR (500 MHz, DMSO-d6) δ 9.75 (s, 1H), 9.08 (d, 1H, J=2.5 Hz), 8.32 (m, 1H), 8.24 (dd, 1H, J=5.0, 1.5 Hz), 7.40 (s, 1H), 7.36 (dd, 1H, J=8.5, 4.5 Hz), 3.45 (s, 3H); MS (APCI+) m/z 281.0 (M+H).

1. customA 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer
2. temperaturereflux condenser and nitrogen inlet
3. customAfter bubbling nitrogen through the resulting solution for 30 min
4. customAfter this time the reaction was partitioned between ethyl acetate (50 mL) and water (50 mL)
5. filtrationfiltered
6. customThe aqueous layer was separated
7. extractionextracted with ethyl acetate (2×25 mL)
8. washwashed with brine (50 mL)
9. dry with materialdried over sodium sulfate
10. customThe drying agent was removed by filtration
11. concentrationthe filtrate concentrated under reduced pressure
12. customThe resulting residue was purified by column chromatography