To a solution of ethyl 2-hydroxybenzoate (0.5 g, 3.0 mmol) in CH2Cl2 (8 mL) was added 2-(tert-butoxycarbonylamino)-3-phenylpropanoic acid (0.8 g, 3.0 mmol), EDCI (0.63 g, 3.3 mmol) and dimethylaminopyridine (0.037 g, 0.3 mmol). The reaction was stirred (RT, 3 h) and then partitioned between CH2Cl2 and brine. The aqueous layer was extracted with CH2Cl2 and the combined organic extracts were dried over MgSO4. The crude material was purified by silica gel chromatography (0-10% MeOH/CH2Cl2) to afford ethyl 2-(2-(tert-butoxycarbonylamino)-3-phenylpropanoyloxy)benzoate (1.2 g). Mass calculated for C235H27NO6=413.46; found: [M+Na]+=437.1.
