3-(Difluoromethoxy)-2-nitropyridine → 3-(Difluoromethoxy)pyridin-2-amine

Temperature

100 °C

[step 2] 3-(Difluoromethoxy)-2-nitropyridine (450 mg, 2.37 mmol) obtained in step 1 was dissolved in ethanol (2 mL)-acetic acid (2 mL), reduced iron (397 mg, 7.10 mmol) was added, and the mixture was stirred at 100° C. overnight. Since the starting material did not disappear, reduced iron (397 mg, 7.10 mmol) was added, and the mixture was further stirred at 100° C. overnight. The mixture was filtered through celite, and the filtrate was concentrated under reduced pressure. To the obtained residue was added saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted 3 times with ethyl acetate. The combined organic layers were dried over anhydrous magnesium sulfate, and purified by silica gel column chromatography (chloroform/methanol=9/1 v/v) to give 3-(difluoromethoxy)pyridin-2-amine (250 mg, 66%).

1. additionwas added
2. stirringthe mixture was further stirred at 100° C. overnight
3. filtrationThe mixture was filtered through celite
4. concentrationthe filtrate was concentrated under reduced pressure
5. additionTo the obtained residue was added saturated aqueous sodium hydrogen carbonate solution
6. extractionthe mixture was extracted 3 times with ethyl acetate
7. dry with materialThe combined organic layers were dried over anhydrous magnesium sulfate
8. custompurified by silica gel column chromatography (chloroform/methanol=9/1 v/v)

ORD record

ord-322186024cd94b3ea25032e9cba6b484

Source dataset

uspto-grants-2015_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08969345B2