反应详情

In 4.0 mL of N,N-dimethylformamide was dissolved 0.39 g of methyl 3-oxo-3,4-dihydro-2-pyrazinecarboxylate. In an atmosphere of nitrogen gas, 90 mg of sodium hydride was added and stirred at room temperature for 2 hours. Then, a suspension of 0.50 g of 4-[(trityloxy)methyl]-2-cyclopenten-1-yl acetate, 0.62 g of tetrakis-triphenylphosphine palladium and 50 mg of triphenylphosphine in 4 mL of tetrahydrofuran was added, and the mixture thus obtained was stirred at room temperature for one hour and thereafter at 60° C. for 4 hours. The reaction mixture was allowed to cool, diluted with 30 mL of ethyl acetate and 20 mL of water, adjusted to pH 4 with 1 mol/L hydrochloric acid, and separated into layers. The organic layer was washed successively with saturated aqueous solution of sodium hydrogen carbonate, water and 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: hexane:ethyl acetate=1:1] to obtain 0.23 g of methyl 3-oxo-4-{4-[(trityloxy)methyl]-2-cyclopenten-1-yl}-3,4-dihydro-2-pyrazinecarboxylate as a light yellow oily product.

1. additionwas added
2. customthe mixture thus obtained
3. stirringwas stirred at room temperature for one hour
4. waitat 60° C. for 4 hours
5. temperatureto cool
6. customseparated into layers
7. washThe organic layer was washed successively with saturated aqueous solution of sodium hydrogen carbonate, water and saturated aqueous solution of sodium chloride
8. dry with materialdried on anhydrous magnesium sulfate
9. customthe solvent was removed under reduced pressure
10. customThe residue was purified by column chromatography [eluent: hexane:ethyl acetate=1:1]