A solution of 5-propyl-1-[2′-(1H-tetrazol-5-yl)-biphenyl-4-ylmethyl]-1H-pyrazole-3-carboxylic acid (200 mg, 510 μmol), HOAt (77.1 mg, 566.4 μmol), EDCI (108.6 mg, 566.4 μmol), and 2,6-lutidine (357.8 μL, 3.1 mmol) in DCM (6.1 mL, 94.7 mmol) was stirred to pre-activate the acid. After 30 minutes, the mixture was cooled at 0° C. and (R)-3-amino-4-phenylbutyric acid hydrochloride (122.2 mg, 566.4 μmol) was added. The resulting solution was slowly warmed to room temperature and stirred overnight. The mixture was then concentrated, re-dissolved in water/MeCN/TFA and purified using reverse phase liquid chromatography to yield the title compound (59 mg; 92% purity). MS m/z: [M+H]+ calcd for C31H31N7O3, 550.25; found 550.4.
