反应详情

2,6-Dibromotoluene (9.8 g, 39 mmol) in THF (300 mL) was stirred under N2 and was then cooled to −100° C. (ether/liquid N2). n-BuLi (16.4 mL, 41 mmol, 2.5 M in hexane) was then added drop wise and after stirring for 5 minutes DMF (4.5 mL, 58.6 mmol) was added. The reaction was stirred for a further 20 minutes and then for an hour at −78° C. The reaction was quenched with saturated aqueous NH4Cl and allowed to warm up to room temperature. The reaction was diluted with water and the pH adjusted to pH 7-8 with sat. aqueous NaHCO3. The mixture was evaporated in vacuo to remove the THF, and the product was then extracted with Et2O (×3). The combined organic layers were washed with brine and dried (MgSO4). The product was filtered and evaporated on vacuo to give 5-bromo-4-methyl-pyridine-3-carbaldehyde as a colourless solid which was used without further purification.

1. additionwas added
2. waitfor an hour at −78° C
3. customThe reaction was quenched with saturated aqueous NH4Cl
4. additionThe reaction was diluted with water
5. customThe mixture was evaporated in vacuo
6. customto remove the THF
7. extractionthe product was then extracted with Et2O (×3)
8. washThe combined organic layers were washed with brine
9. dry with materialdried (MgSO4)
10. filtrationThe product was filtered
11. customevaporated on vacuo