反应详情

Methanol (1.48 g, 46.1 mmol) is slowly added to a cooled suspension (0° C.) of NaH (2.12 g, 53.2 mmol, 60% dispersion in mineral oil, washed with hexane prior to use) in THF (20 mL). Upon completion of the addition the mixture is stirred at 0° C. for 150 min before 2,6-dibromo-4-nitropyridine (10.0 g, 35.4 mmol) is added. The temperature rises to 14° C. The mixture is stirred at rt for 3 h before the reaction is quenched with sat. aq. NH4Cl solution. The mixture is diluted with water and extracted twice with EA (250 mL). The combined org. extracts are dried over MgSO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with DCM to give 2,6-dibromo-4-methoxy-pyridine (6.43 g) as an off-white solid; LC-MS: tR=0.90 min, [M+1]+=267.75.

1. washwashed with hexane
2. additionUpon completion of the addition the mixture
3. additionis added
4. customrises to 14° C
5. customis quenched with sat. aq. NH4Cl solution
6. additionThe mixture is diluted with water
7. extractionextracted twice with EA (250 mL)
8. dry with materialextracts are dried over MgSO4
9. filtrationfiltered
10. concentrationconcentrated
11. customThe crude product is purified by CC on silica gel eluting with DCM