2-Nitro-4-(trifluoromethyl)phenol → 2-Amino-4-(trifluoromethyl)phenol

Temperature

55 °C

Sodium dithionite (97.0 g, 0.5 mole) was added in portions over a period of 6 hours to a solution of 2-nitro-4-trifluoromethylphenol (31 g, 0.15 mole) in a mixture of ethanol (120 ml) and water (90 ml), the solution being heated, with stirring, at a temperature of 55° C. during the addition. The mixture was filtered, the filtrate retained, and the collected solid was triturated with ethanol and refiltered. The solvent was removed from the combined filtrates by distillation under reduced pressure to give a yellow solid. The solid was dissolved in water, the aqueous solution extracted with diethyl ether (4×100 ml) and the combined ethereal phases were washed with brine. The ethereal phase was dried over anhydrous magnesium sulfate and the solvent evaporated to give a yellow solid which was recrystallised from petroleum ether (700 ml, bp 100°-120° C.) to give the title compound as a pale yellow solid (10.6 g).

1. temperaturethe solution being heated
2. filtrationThe mixture was filtered
3. customthe collected solid was triturated with ethanol
4. customThe solvent was removed from the combined filtrates by distillation under reduced pressure
5. customto give a yellow solid
6. extractionthe aqueous solution extracted with diethyl ether (4×100 ml)
7. washthe combined ethereal phases were washed with brine
8. dry with materialThe ethereal phase was dried over anhydrous magnesium sulfate
9. customthe solvent evaporated
10. customto give a yellow solid which
11. customwas recrystallised from petroleum ether (700 ml, bp 100°-120° C.)

ORD record

ord-6334f43f584f463aa5a189d3bf5ff654

Source dataset

uspto-grants-1982_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04314065