反应详情

Stir a suspension of 137 mg (0.36 mmol) of (bis-benzonitrile)-palladium II dichloride and 183 mg (0.43 mmol) of diphenylphosphinobutane in 7 mL of toluene under argon for 30 min at room temperature. Then add, while bubbling with argon, 1.66 g (7.15 mmol) of methyl 5-amino-6-bromopyrazine-2-carboxylate, 1.97 g (7.51 mmol) of [3-(benzyloxy)-4-chlorophenyl]boronic acid, 2.4 mL of ethanol and 3.58 mL (7.15 mmol) of a 2N aqueous solution of sodium carbonate. Reflux the reaction mixture for 5 h 30 min and then distribute in 100 mL of a water/EtOAc 1:1 mixture. Wash the organic phase with 50 mL of water, dry over Na2SO4 and concentrate under reduced pressure. Purify the residue, obtained by silica gel column chromatography, eluting with a cyclohexane/EtOAc gradient from 50 to 100% of EtOAc. After concentration under reduced pressure, we obtain 1.33 g of methyl 5-amino-6-[3-(benzyloxy)-4-chlorophenyl]pyrazine-2-carboxylate in the form of yellow wax.

1. additionThen add
2. temperatureReflux the reaction mixture for 5 h 30 min
3. washWash the organic phase with 50 mL of water
4. dry with materialdry over Na2SO4
5. concentrationconcentrate under reduced pressure
6. customPurify the residue
7. customobtained by silica gel column chromatography
8. washeluting with a cyclohexane/EtOAc gradient from 50 to 100% of EtOAc
9. concentrationAfter concentration under reduced pressure, we