反应详情

A mixture of Pd(OAc)2 (146 mg, 0.7 mmol) and 1,1-bis(diphenylphosphino)ferrocene (478 mg, 0.9 mmol) in DMF (65 ml) under an argon atmosphere was stirred at 50° for 15 min and cooled to rt. The reaction mixture was evacuated, then flushed with argon. 3-Amino-6-bromopyrazine-2-carboxylic acid methyl ester (5.0 g, 21.5 mmol), 2-furanboronic acid (2.65 g, 23.7 mmol) and triethylamine (4.3 ml) were added. The reaction mixture was again evacuated, then flushed with argon. The mixture was heated at 90° overnight. After cooling to rt, the black mixture was concentrated to dryness. The residue was dissolved in dichloromethane (800 ml), washed with water, dried over MgSO4, filtered and evaporated. The crude product was purified by silica gel chromatography using a n-heptane/EtOAc gradient for elution, providing the title compound as yellow solid (2.84 g, 60%).

1. customThe reaction mixture was evacuated
2. customflushed with argon
3. customThe reaction mixture was again evacuated
4. customflushed with argon
5. temperatureThe mixture was heated at 90° overnight
6. temperatureAfter cooling to rt
7. concentrationthe black mixture was concentrated to dryness
8. dissolutionThe residue was dissolved in dichloromethane (800 ml)
9. washwashed with water
10. dry with materialdried over MgSO4
11. filtrationfiltered
12. customevaporated
13. customThe crude product was purified by silica gel chromatography
14. washfor elution