Hydrochloric Acid → 2-(Difluoromethyl)-4-fluoroaniline

Under a nitrogen atmosphere, to a solution of the above 2-(difluoromethyl)-4-fluoro-1-nitrobenzene (5.9 g, 31 mmol) in ethanol (0.10 L), stannous chloride dihydrate (28 g, 0.12 mol) and concentrated hydrochloric acid (20 mL) were successively added under ice-cooling, and the mixture was stirred at room temperature for 1 hour. After the reaction, ethanol was distilled off under reduced pressure and a 5M aqueous sodium hydroxide solution was added under ice-cooling to make it basic. Thereafter, it was extracted with diethyl ether and after it was successively washed with water and saturated brine, it was dried with sodium sulfate and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane, 1:4, v/v) to give the title compound (3.0 g, 60%) as an oil.

1. temperaturecooling
2. distillationwas distilled off under reduced pressure
3. additiona 5M aqueous sodium hydroxide solution was added under ice-
4. temperaturecooling
5. extractionThereafter, it was extracted with diethyl ether
6. washafter it was successively washed with water and saturated brine, it
7. dry with materialwas dried with sodium sulfate
8. distillationthe solvent was distilled off under reduced pressure
9. customThe residue was purified by silica gel column chromatography (ethyl acetate/hexane, 1:4, v/v)

ORD record

ord-e806954345ab4dea98e0acc0a1d25fed

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08642640B2