Trifluoroacetic acid → 1,2-Difluoro-5-methyl-3-nitrobenzene

3,4-Difluorotoluene (9.00 g, 70.3 mmol), ammonium nitrate (6.75 g, 84.3 mmol) and trifluoroacetic acid (25 ml) were stirred at ambient temperature for 18 h. The resulting solution was made basic to pH>10 with 5 N sodium hydroxide and, after cooling to ambient temperature, extracted with diethyl ether (3×40 ml). The combined organic layers were washed with brine (40 ml) and dried over anhydrous sodium sulfate. The filtrate was concentrated in vacuo. The crude product was purified by silica gel column chromatography, eluting with hexanes/ethyl acetate (9:1), to afford 3,4-difluoro-5-nitrotoluene (4.63 g, 40%) as a light yellow oil. 1H-NMR δ(400 MHz, CDCl3) 7.94 (1H, dd, J=9.9, 7.3 Hz), 7.17 (1H, dd, J=10.3, 7.6 Hz), 2.61 (3H, s).

1. extractionextracted with diethyl ether (3×40 ml)
2. washThe combined organic layers were washed with brine (40 ml)
3. dry with materialdried over anhydrous sodium sulfate
4. concentrationThe filtrate was concentrated in vacuo
5. customThe crude product was purified by silica gel column chromatography
6. washeluting with hexanes/ethyl acetate (9:1)

ORD record

ord-83c979e9e8e84603882e58746747e4df

Source dataset

uspto-grants-2004_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06777437B2