2,3,5,6-Tetrafluorophenol → N-(1-methyl-3-isobutyl-indole-2-cabonyl)-valinyl-3-amino-4-oxo-5-(2,3,5,6-tetrafluorophenyloxy)-pentanoic acid, tert-butyl ester

Participants

Reaction Steps

Potassium fluoride (21.6 mg, 0.37 mmol) was added to a solution of N-[(1-methyl-3-isobutyl-indole-2-cabonyl)valinyl]-3-amino-5-bromo-4-oxo-pentanoic acid, tert-butyl ester (86.1 mg, 0.149 mmol) and 2,3,5, 6-tetrafluorophenol (27.0 mg, 0.163 mmol in DMF (2.0 ml). After stirring at room temperature for 3 hours, the reaction mixture was partitioned between ethyl acetate and water. The aqueous layer was back-extracted with ethyl acetate. The organic layers were combined, washed with saturated NaHCO3 solution, and brine, dried over sodium sulfate, and concentrated. The residue was triturated with ether to give the titled product, N-(1-methyl-3-isobutyl-indole-2-cabonyl)-valinyl-3-amino-4-oxo-5-(2,3,5,6-tetrafluorophenyloxy)-pentanoic acid, tert-butyl ester as a white solid (43.8 mg, 44%). TLC (hexane/EtOAc, 50/50): Rf=0.50.

Provenance & Evidence