反应详情

温度

80 °C

In an atmosphere of nitrogen gas, 11.4 g of methyl 6-bromo-3-methoxy-2-pyrazinecarboxylate was dissolved in 227 mL of toluene, and 10.3 g of benzophenoneimine, 0.42 g of tris(dibenzylideneacetone)dipalladium, 0.86 g of (s)-(−)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl and 6.20 g of sodium tert-butoxide were successively added. The mixture thus obtained was stirred at 80° C. for one hour. After cooling the reaction mixture, it was filtered. The filtrate was purified by column chromatography [eluent: toluene:ethyl acetate=20:1]. The oily product thus obtained was dissolved in 140 mL of tetrahydrofuran, 7 mL of 2 mol/L hydrochloric acid was added, and the mixture thus obtained was stirred at room temperature for 15 minutes. A mixture of 200 mL of chloroform and 50 mL of water was added to the reaction mixture and then 1 mol/L sodium hydroxide was added to alkalinize the mixture, and the organic layer was separated. The organic layer thus obtained was washed with a saturated aqueous solution of sodium chloride and dried on anhydrous magnesium sulfate, and the solvent was removed under reduced pressure. The residue was purified by column chromatography [eluent: toluene:ethyl acetate=1:1] to obtain 3.64 g of methyl 6-amino-3-methoxy-2-pyrazinecarboxylate as a yellow-colored oily product.

1. customThe mixture thus obtained
2. temperatureAfter cooling the reaction mixture, it
3. filtrationwas filtered
4. customThe filtrate was purified by column chromatography [eluent: toluene:ethyl acetate=20:1]
5. customThe oily product thus obtained
6. customthe mixture thus obtained
7. stirringwas stirred at room temperature for 15 minutes
8. additionwas added to the reaction mixture
9. customthe organic layer was separated
10. customThe organic layer thus obtained
11. washwas washed with a saturated aqueous solution of sodium chloride
12. dry with materialdried on anhydrous magnesium sulfate
13. customthe solvent was removed under reduced pressure
14. customThe residue was purified by column chromatography [eluent: toluene:ethyl acetate=1:1]