Dimethylformamide → 2-Bromo-6-fluorobenzaldehyde

Temperature

-75 °C

n-Butyllithium (2.5 M solution in hexanes; 91 ml) was added dropwise under nitrogen at 0° C. to a stirred solution of diisopropylamine (35 ml) in tetrahydrofuran (450 ml), then the mixture was cooled to −75° C., 3-bromofluorobenzene (25 ml) was added over 10 minutes and the mixture was stirred at −75° C. for 1 hour. Dimethylformamide (19.3 ml) was added dropwise at −70° C. over 5 minutes, the mixture was stirred for 10 minutes, then acetic acid (20 ml) and water (700 ml) were added. The mixture was allowed to warm to 10° C. and the product was extracted into ether (500+300 ml). The combined extracts were washed with water (2×500 ml), 0.2M hydrochloric acid (500 ml) and saturated aqueous sodium chloride solution (2×250 ml), then they were dried (Na2SO4) and the solvents were removed in vacuo to give 2-bromo-6-fluorobenzaldehyde (40.18 g) as an off-white solid, m.p. 35-37° C.

1. stirringthe mixture was stirred for 10 minutes
2. temperatureto warm to 10° C.
3. extractionthe product was extracted into ether (500+300 ml)
4. washThe combined extracts were washed with water (2×500 ml), 0.2M hydrochloric acid (500 ml) and saturated aqueous sodium chloride solution (2×250 ml)
5. dry with materialthey were dried (Na2SO4)
6. customthe solvents were removed in vacuo

ORD record

ord-005b175d0faf49d1887eca1ab567d84d

Source dataset

uspto-grants-2005_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06900216B2