Sulfuric Acid → 2,6-Difluorobenzaldehyde

Temperature

-50 °C

1,3-Difluorobenzene (25 g., 0.22 mole) was dissolved in 150 ml. of tetrahydrofuran and cooled to -50° C. Butyl lithium (99 ml. of 2.3M in hexane, 0.228 mole) was added over 20 minutes, maintaining the temperature at -50° C. After 1.5 hours of stirring at the same temperature, N-methylformanilide (29.7 g., 0.22 mole) in 50 ml. of tetrahydrofuran was added over 20 minutes at -50° C. After an additional 1.5 hours of stirring at -50° C., the reaction mixture was poured slowly into 1 liter of cold 1N sulfuric acid, and extracted with three portions of ether. The combined organic extracts were washed with brine, dried over anhydrous magnesium sulfate, filtered and concentrated to an oil. The oil was distilled. Middle cuts were combined to yield 2,6-difluorobenzaldehyde (18.2 g., 58%; b.p. 72°-74°/12 mm.).

1. extractionextracted with three portions of ether
2. washThe combined organic extracts were washed with brine
3. dry with materialdried over anhydrous magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated to an oil
6. distillationThe oil was distilled

ORD record

ord-e17d556722e24279b8c162ead0459382

Source dataset

uspto-grants-1984_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04448971