Hydrochloric Acid → Benzyl[4-(2-aminopyridin-4-yloxy)-2-fluorophenyl]carbamate

Participants

Reaction Steps

A 4N solution of hydrochloric acid in ethyl acetate solution (120 ml) was cooled in an ice bath. To this was added tert-butyl [4-(4-benzyloxycarbonylamino-3-fluorophenoxy)pyridin-2-yl]carbamate (3.92 g) while stirring and the mixture was further stirred for 10 minutes in an ice bath. The reaction mixture was then further stirred for 3.5 hours at room temperature. The reaction mixture was concentrated under reduced pressure. Ethyl acetate (150 ml) and a saturated aqueous solution of sodium hydrogencarbonate (70 ml) were then added and partitioned. The aqueous layer was extracted with ethyl acetate (50 ml). The combined organic layers were washed with brine and dried over anhydrous sodium sulfate. The dried organic layer was concentrated under reduced pressure. The obtained crystals were suspended in a mixed solvent of hexane and ethyl acetate (5:1). The crystals were collected by filtration and washed with a mixed solvent of hexane and ethyl acetate (5:1). The crystals were then suction-dried at room temperature to give the title compound as pale yellow crystals (2.93 g, 95.9%).

Provenance & Evidence