反应详情

A mixture of tert-butyl{4-chloro-2-fluoro-5-[(5-nitropyridin-2-yl)oxy]phenyl}carbamate (4.66 g, 12.1 mmol), reduced iron (61.2 mmol), calcium chloride (680 mg, 6.13 mmol) and ethanol (90 mL)/water (10 mL)/1-methyl-2-pyrrolidone (40 mL) was stirred with heating under reflux for 5 hr. Reduced iron (5.00 g, 89.5 mmol) and calcium chloride (700 mg, 6.31 mmol) were further added, and the mixture was stirred with heating under reflux for 16 hr. The reaction mixture was filtered through celite, and the filtrate was concentrated under reduced pressure. The residue was diluted with ethyl acetate (300 mL), and washed with water (100 mL×2) and saturated brine (50 mL). The obtained organic layer was dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by basic silica gel column chromatography (hexane/ethyl acetate=90/10→10/90) to give the title compound (2.45 g, 57%) as a yellow powder.

1. temperaturewith heating
2. temperatureunder reflux for 5 hr
3. stirringthe mixture was stirred
4. temperaturewith heating
5. temperatureunder reflux for 16 hr
6. filtrationThe reaction mixture was filtered through celite
7. concentrationthe filtrate was concentrated under reduced pressure
8. additionThe residue was diluted with ethyl acetate (300 mL)
9. washwashed with water (100 mL×2) and saturated brine (50 mL)
10. dry with materialThe obtained organic layer was dried over anhydrous magnesium sulfate
11. concentrationconcentrated under reduced pressure
12. customThe residue was purified by basic silica gel column chromatography (hexane/ethyl acetate=90/10→10/90)