反应详情

温度

110 °C

Methyl 3-amino-6-bromo-pyrazine-2-carboxylate (6.012 g, 25.91 mmol), [4-(dimethylcarbamoyl)phenyl]boronic acid (5 g, 25.91 mmol), sodium carbonate (5.492 g, 51.82 mmol) and Pd(PPh3)4 (2.994 g, 2.591 mmol) in a mixture of acetonitrile (28.85 mL) and water (28.85 mL) was heated at 110° C. The reaction mixture was allowed to cool and the residual solid filtered off. The filtrate was diluted with EtOAc and water and the layers separated. The aqueous layer was acidified to pH4 (by addition of 1M HCl) and then extracted with dichloromethane (3×), dried (MgSO4), filtered and concentrated in vacuo to leave the product as a yellow solid. The ethyl acetate extracts were concentrated in vacuo and combined with the filtered solid. Preabsorbed onto silica and purified by column chromatography on silica using the companion eluting with ethyl acetate/petroleum ether (0-100% EtOAc). Product eluted with 100% EtOAc. Product fractions combined and conc in vacuo to leave a yellow solid (1.95 g, 50% Yield). 1H NMR (400.0 MHz, DMSO) d 3.02 (3H, s), 3.15 (3H, s), 4.04 (3H, s), 7.54 (2H, m), 7.97 (2H, m), 8.71 (1H, s) ppm; MS (ES+) 301.13

1. temperatureto cool
2. filtrationthe residual solid filtered off
3. additionThe filtrate was diluted with EtOAc and water
4. customthe layers separated
5. additionThe aqueous layer was acidified to pH4 (by addition of 1M HCl)
6. extractionextracted with dichloromethane (3×)
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated in vacuo