Dimethylformamide → 6-Bromopyridine-2-carbaldehyde

Temperature

-10 °C

n-Butyllithium (337 mmol) in 1.52M hexane solution (222 mL) was dissolved in toluene (500 mL) cooled at −10° C., and n-butylmagnesium chloride (169 mmol) in 2.00M tetrahydrofuran solution (84.5 ml) was added dropwise below −10° C. over a period of 25 minutes. After stirring at −10° C. for one hour, 2,6-dibromopyridine (100 g, 422 mmol) in toluene (1000 mL) was added dropwise to the mixture at an inside temperature of −10° C. to −6° C. over one hour. The mixture was further stirred at −10° C. for 1.5 hours and then N,N-dimethylformamide (65 mL, 840 mmol) was added dropwise below −2° C. over 20 minutes. After further stirring at 0° C. for one hour, 10% aqueous acetic acid solution (750 mL) was added. The mixture was stirred under ice-cooling and the organic phase was separated. The extract was washed with saturated aqueous sodium chloride (25 mL), dried over anhydrous sodium sulfate and concentrated to give 6-bromo-2-formylpyridine (74.68 g, 98% purity, 95% yield) as a pale yellowish solid.

1. stirringThe mixture was further stirred at −10° C. for 1.5 hours
2. stirringAfter further stirring at 0° C. for one hour
3. stirringThe mixture was stirred under ice-
4. temperaturecooling
5. customthe organic phase was separated
6. washThe extract was washed with saturated aqueous sodium chloride (25 mL)
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated

ORD record

ord-e57ee3721fe84e498d8e89e5f288ba26

Source dataset

uspto-grants-2008_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07439535B2