Ethanol → Tert-butyl{5-[(5-aminopyridin-2-yl)oxy]-4-chloro-2-fluorophenyl}carbamate

Participants

Reaction Steps

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.

Provenance & Evidence