A mixture of (R)-2-amino-2-(4-fluorophenyl)ethanol (68.6 mg, 0.44 mmol), (S)-4-(4-(tert-butoxycarbonyl)morpholin-2-yl)benzoic acid [CAS 1131220-40-0], (136 mg, 0.44 mmol), 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (170 mg, 0.88 mmol), 4-dimethylaminopyridine (54.0 mg, 0.44 mmol) and triethylamine (179 mg, 0.25 ml, 1.77 mmol) in dichloromethane (9 ml) was stirred at room temperature overnight. The reaction was quenched by addition of 1M citric acid solution (5 ml). The organic layer was separated, washed with sodium bicarbonate saturated solution (5 ml), dried over MgSO4 and evaporated. The crude material was purified by flash chromatography (silica gel, gradient heptane/ethyl acetate), to give a white foam (100 mg, 51%), MS (ISP): 445.4 (100%, [M-tBu+H]+), 389.3 (29%, [M+H]+).
