Dimethylformamide → 6-Bromopyridine-2-carbaldehyde

Temperature

-70 °C

To THF(60 ml) was added at −70° C. n-butyllithium (1.59M hexane solution, 63 ml, 100 mmol). To the mixture was added dropwise (taking about 1 hour) a solution of 2,6-dibromo-pyridine (23.69 g, 100 mmol) in THF (140 ml) at −60° C., and the mixture was stirred at −70° C. for 15 minutes. To the mixture was added DMF (12 ml), and the mixture was stirred at the same temperature for 15 minutes. To the mixture was added 20% ammonium chloride solution (100 ml), and the organic layer was separated. The aqueous layer extracted with ethyl acetate (100 ml), and the organic layer was mixed with the previous organic layer. The organic layer was dried with anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified with column chromatography (silica gel 150 g, ethyl acetate/hexane=1/20), and the desired fraction was concentrated under reduced pressure. To the residue was added duisopropyl-ether (15 ml), and insoluble materials were filtered, which were washed with diisopropylether (5 ml×3) and dried under reduced pressure to give 6-bromo-2-pyridinecarbaldehyde (2.05 g, 11.0 mmol, 11%).

1. stirringthe mixture was stirred at the same temperature for 15 minutes
2. customthe organic layer was separated
3. extractionThe aqueous layer extracted with ethyl acetate (100 ml)
4. additionthe organic layer was mixed with the previous organic layer
5. dry with materialThe organic layer was dried with anhydrous sodium sulfate
6. concentrationconcentrated under reduced pressure
7. customThe residue was purified with column chromatography (silica gel 150 g, ethyl acetate/hexane=1/20)
8. concentrationthe desired fraction was concentrated under reduced pressure
9. additionTo the residue was added duisopropyl-ether (15 ml), and insoluble materials
10. filtrationwere filtered
11. washwhich were washed with diisopropylether (5 ml×3)
12. customdried under reduced pressure

ORD record

ord-1583d4b5be9941a4b9da678db1aa3823

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06268354B1