Hydrochloric Acid → [4-(2-Aminopyridin-4-yloxy)-3-fluorophenyl]carbamic acid benzyl ester

Participants

Reaction Steps

To a 4N solution of hydrochloric acid in ethyl acetate (30 ml) was added [4-(4-benzyloxycarbonylamino-2-fluorophenoxy)pyridin-2-yl]carbamic acid tert-butyl ester (510 mg) while stirring in an ice water bath. The reaction mixture was allowed to warm up to room temperature, followed by stirring for 16 hr. To the reaction mixture were added diethyl ether (10 ml) and a 5N aqueous solution of sodium hydroxide (1 ml), followed by stirring for 30 min. The separated organic layer was washed with a saturated aqueous solution of sodium hydrogencarbonate (20 ml), water (20 ml) and brine (20 ml), and dried over anhydrous sodium sulfate. The solvent was removed under reduced pressure, the resultant residue was purified by silica gel column chromatography (Fuji Silysia NH, eluent; heptane:ethyl acetate=1:2) and fractions containing the target compound were concentrated under reduced pressure. To the resultant residue were added diethyl ether (4 ml) and hexane (6 ml) to suspend the precipitated solid. The solid was collected by filtration and dried under aeration to provide the titled compound as pale yellow powder (46.6 mg, 11.7%).

Provenance & Evidence