反应详情

4-Chloro-3-nitro-6-trifluoromethyl-pyridin-2-ol (65.1 gm 268 mmol) was dissolved in tetrahydrofuran (350 mL) and stirred at room temperature under N2. Benzylamine (86.3 gm 805 mmol) in tetrahydrofuran (50 mL) was added drop wise over 30 minutes to give a bright yellow solution. The reaction was heated in an oil bath at 50° C. for 18 hours, (a solid formed during the reaction). Cooled to ambient temperature, diluted the reaction mixture with diethyl ether (200 mL) and filtered off the solid (benzylamine hydrochloride). The filtrate was evaporated to low bulk under reduced pressure to give a thick yellow slurry. Added diethyl ether (300 mL) and filtered off the yellow solid, dried on the filter pad to give the benzylamine salt (96.5 gm). The desired product was liberated by partition of the solid between aqueous 2N HCl and dichloromethane and crystallization from ethyl acetate/n-pentane gave 4-benzylamino-3-nitro-6-trifluoromethyl-pyridin-2-ol as a pale yellow solid (61.7 gm 73.4% yield).

1. customto give a bright yellow solution
2. temperatureThe reaction was heated in an oil bath at 50° C. for 18 hours
3. custom(a solid formed during the reaction)
4. temperatureCooled to ambient temperature
5. filtrationfiltered off the solid (benzylamine hydrochloride)
6. customThe filtrate was evaporated to low bulk under reduced pressure
7. customto give a thick yellow slurry
8. filtrationAdded diethyl ether (300 mL) and filtered off the yellow solid
9. customdried on the filter pad