Triphenylphosphine → 3,5-dichloro-N-trifluoroacetyl-O-[(2-phenyl)-benzoxazol-7-yl]methyl-L-tyrosine methyl ester

Participants

Reaction Steps

Diethylazodicarboxylate (40% toluene solution 0.63 ml) was added dropwise to a solution of 3,5-dichloro-N-trifluoroacetyl-L-tyrosine methyl ester (252 mg, 0.7 mmol), [(2-phenyl)-benzoxazol-7-yl]methanol (193 mg, 0.857 mmol) and triphenylphosphine (374 mg, 1.43 mmol) in tetrahydrofuran (3 ml) under argon atmosphere at 5° C., and the mixture was stirred at the same temperature for 60 hrs. The solvent of the reaction mixture was distilled off under reduced pressure. The residue was purified by column chromatography on silica gel (n-hexane/ethyl acetate=4) to give 3,5-dichloro-N-trifluoroacetyl-O-[(2-phenyl)-benzoxazol-7-yl]methyl-L-tyrosine methyl ester (324 mg, 82%) as colorless crystals.

Provenance & Evidence