Dimethylformamide → 3,5-dichloro-N-trifluoroacetyl-O-[(2-phenylbenzo[b]fur-7-yl)methyl]-L-tyrosine methyl ester

Participants

Reaction Steps

Potassium carbonate (180 mg, 1.30 mmol) and 7-chloromethyl-2-phenylbenzo[b]furan. (171 mg, 0.705 mmol) were added in turn to a solution of 3,5-dichloro-N-trifluoroacetyl-L-tyrosine methyl ester (221 mg, 0.614 mmol) in acetone (3 ml) with stirring under ice cooling and the mixture was stirred under argon atmosphere at the same temperature for 5 hrs. Dimethylformamide (2 ml) and n-tetrabutylammonium iodide (23 mg, 0.062 mmol) were added to the mixture and stirred at room temperature for 21 hrs. The reaction mixture was poured into ice-water (50 ml) and extracted with ethyl acetate. The extract was washed with water and saturated brine solution in turn and dried. The solvent was distilled off under reduced pressure. The residue was purified by flash column chromatography on silica gel (n-hexane/ethyl acetate=5) to give 3,5-dichloro-N-trifluoroacetyl-O-[(2-phenylbenzo[b]fur-7-yl)methyl]-L-tyrosine methyl ester (182 mg, 52%) as colorless crystals.

Provenance & Evidence