Dimethylformamide → 6-Bromopyridine-2-carbaldehyde

Temperature

-78 °C

To a stirred solution of 2.5 M n-butyllithium in hexane (8.6 mL, 21.5 mmol) under N2, cooled to −78° C., was added dropwise a solution of 2,6-dibromopyridine (5.10 g, 21.5 mmol) in dry THF (30 mL) at such a rate that the internal temperature was below −70° C. After complete addition, the reaction mixture was stirred at −78° C. for 15 min, and then treated with anhydrous DMF (2.6 mL, 33.3 mmol). After 15 min, the reaction mixture was treated successively with acetic acid (1.36 mL) and water (21.5 mL) and then warmed to RT. The reaction mixture was poured into ethyl acetate (75 mL). The phases were separated. The aqueous phase was extracted with ethyl acetate (25 mL). The combined organic phases were washed with brine (35 mL), dried (MgSO4), filtered and concentrated to afford 3.33 g (18.0 mmol, 84%) of the desired product as a white solid.

1. customwas below −70° C
2. additionAfter complete addition
3. waitAfter 15 min
4. temperaturewarmed to RT
5. customThe phases were separated
6. extractionThe aqueous phase was extracted with ethyl acetate (25 mL)
7. washThe combined organic phases were washed with brine (35 mL)
8. dry with materialdried (MgSO4)
9. filtrationfiltered
10. concentrationconcentrated

ORD record

ord-fc2a3fe04c3f4fedb1f8bc7a7dad0d72

Source dataset

uspto-grants-2008_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07417041B2