反应详情

3,5-Dichloro-pyrazine-2-carbaldehyde (5.0 g) was dissolved in dry tetrahydrofuran (100 ml) in a reaction vessel equipped with a magnetic stirring bar under an argon atmosphere. The solution was cooled on an ice-bath before slow addition of 10.3 ml methylmagnesium bromide solution (3M in tetrahydrofuran), keeping the internal temperature in the reaction vessel below 5° C. After the addition the cooling bath was removed and the reaction mixture stirred for another 10 min. Then the reaction mixture was quenched with a saturated aqueous sodium bicarbonate solution (100 ml) and extracted with EtOAc (3×200 ml). The combined aqueous phases were dried over sodium sulfate, filtered and evaporated to afford 1-(3,5-dichloro-pyrazin-2-yl)-ethanol as a dark brown oil. Yield: 5.23 g (96%).

1. customequipped with a magnetic stirring bar under an argon atmosphere
2. customin the reaction vessel below 5° C
3. additionAfter the addition the cooling bath
4. customwas removed
5. customThen the reaction mixture was quenched with a saturated aqueous sodium bicarbonate solution (100 ml)
6. extractionextracted with EtOAc (3×200 ml)
7. dry with materialThe combined aqueous phases were dried over sodium sulfate
8. filtrationfiltered
9. customevaporated