反应详情

6-(5-Chloro-2-pyridyl)-6,7-dihydro-7-hydroxy-5H-pyrrolo[3,4-b]pyrazin-5-one (1.05 g) and ethoxycarbonylmethylenetriphenylphosphorane (1.39 g) were dissolved in dry toluene (30 ml) and the solution was refluxed for 6 hours. After cooling, the solvent was distilled off and the residue was purified by silica gel column chromatography. Fractions eluted with dichloromethaneethyl acetate (2:1) were collected and the solvent was distilled off to give crude crystals. Recrystallization from ether-dichloromethane (5:1) gave 1.2 g of 6-(5-chloropyridyl)-6,7-dihydro-7-ethoxycarbonylmethyl-5H-pyrrolo[3,4-b]pyrazin-5-one.

1. temperaturethe solution was refluxed for 6 hours
2. temperatureAfter cooling
3. distillationthe solvent was distilled off
4. customthe residue was purified by silica gel column chromatography
5. washFractions eluted with dichloromethaneethyl acetate (2:1)
6. customwere collected
7. distillationthe solvent was distilled off
8. customto give crude crystals
9. customRecrystallization from ether-dichloromethane (5:1)