Dimethylformamide → 2,4-dibromo-6-fluorobenzaldehyde

Temperature

-78 °C

In a flame-dried 250 mL round-bottomed flask equipped with an addition funnel and magnetic stirrer, a mixture of diisopropylamine (4.82 mL, 34.66 mmol) in 100 mL of anhydrous THF was cooled to −78° C. and treated with 2.5N n-butyllithium (13.86 mL, 34.66 mmol) in THF, dropwise. After stirring for 10 minutes a mixture of 3,5-dibromo-1-fluorobenzene (8.0 g, 31.51 mmol) in 16 mL of THF was added dropwise and stirring was continued for an additional 30 minutes. At this point, N,N-dimethylformamide (DMF) (2.68 mL, 34.66 mmol) was added dropwise and stirring continued another 10 minutes at −78° C. The reaction was quenched with saturated aqueous ammonium chloride and the solvent removed on a rotary evaporator. The residue was dissolved in ether, washed with saturated brine and dried over calcium sulfate, filtered and concentrated to an oil, 7.36 g. Purification by flash chromatography using ethyl acetate-hexanes (1:99) gave the title product as a white solid.

1. customIn a flame-dried 250 mL round-bottomed flask equipped with an addition funnel and magnetic stirrer
2. additionwas added dropwise
3. stirringstirring
4. waitwas continued for an additional 30 minutes
5. stirringstirring
6. waitcontinued another 10 minutes at −78° C
7. customThe reaction was quenched with saturated aqueous ammonium chloride
8. customthe solvent removed on a rotary evaporator
9. dissolutionThe residue was dissolved in ether
10. washwashed with saturated brine
11. dry with materialdried over calcium sulfate
12. filtrationfiltered
13. concentrationconcentrated to an oil, 7.36 g
14. customPurification by flash chromatography

ORD record

ord-a59242cc38bc459289e52065121bdc6c

Source dataset

uspto-grants-2003_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06562813B2