Dimethylformamide → 6-Bromopyridine-2-carbaldehyde

Temperature

-70 °C

A three necked 100 mL round-bottomed flask with magnetic stirring, an immersion thermometer, and an addition funnel was charged with THF (30 mL) and cooled to −78° C. n-butyllithium (1.35 g, 21.10 mmol) was carefully added to the reaction maintaining an internal temperature of −70° C. After the addition of 2,6-dibromopyridine (5.0 g, 21.10 mmol), the resulting dark green solution was stirred for 15 min, then neat DMF (2.31 g, 31.66 mmol) was added over a period of 30 seconds. The reaction mass was stirred for 15 min at −70° C. The progress of the reaction was monitored by TLC analysis on silica gel with ethyl acetate:hexane (3:7) as mobile phase. Reaction mixture was poured into saturated NH4Cl (50 mL) and extracted with EtOAc (3×50 mL). The combined organic layers were washed with brine solution (3×50 mL), dried over MgSO4, filtered, and concentrated by rotary evaporation to afford 5.0 g of crude compound which was purified by chromatography. Product elute at 3% ethyl acetate in hexane to give 1.5 g of pure product (Yield 38.4%).

1. additionwas carefully added to the reaction
2. stirringThe reaction mass was stirred for 15 min at −70° C
3. customReaction mixture
4. extractionextracted with EtOAc (3×50 mL)
5. washThe combined organic layers were washed with brine solution (3×50 mL)
6. dry with materialdried over MgSO4
7. filtrationfiltered
8. concentrationconcentrated by rotary evaporation
9. customto afford 5.0 g of crude compound which
10. customwas purified by chromatography
11. washProduct elute at 3% ethyl acetate in hexane

ORD record

ord-2685cd09b4f74ef5a543099a0ca7330e

Source dataset

uspto-grants-2016_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09428490B2