Diisopropylethylamine → 2-(4-(Cyclopropylmethoxy)-3-fluorophenyl)-1,3-benzoxazol-6-ol

Participants

Reaction Steps

To a solution of 4-aminoresorcinol hydrochloride (5.00 g), 4-(cyclopropylmethoxy)-3-fluorobenzoic acid (5.91 g) and diisopropylethylamine (7.37 mL) in DMF (50 mL) was added HATU (11.8 g), and the mixture was stirred at room temperature for 1 hr. The reaction mixture was diluted with ethyl acetate, washed with saturated brine, and dried over anhydrous magnesium sulfate. The solvent was evaporated under reduced pressure, and the obtained solid was washed with ethyl acetate. To a solution of the obtained solid, hexachloroethane (16.7 g) and triphenylphosphine (18.5 g) in acetonitrile (50 mL) was added triethylamine (11.8 mL), and the mixture was stirred at room temperature for 15 min, and then with heating at 80° C. for 2 hr. The reaction mixture was filtered, the solvent was evaporated under reduced pressure, and the residue was purified by silica gel column chromatography (hexane/ethyl acetate) to give the title compound (2.23 g).

Provenance & Evidence