To a mixture of 4′-methyl-5-((6-methylpyridin-3-yl)methylcarbamoyl)-biphenyl-3-carboxylic acid (55 mg, 0.15 mmol), N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride (58 mg, 0.30 mmol), 1-hydroxybenzotriazole hydrate (23 mg, 0.15 mmol), and CH2Cl2 (3 mL) were added (R)-3-hydroxypyrrolidine (26 mg, 0.30 mmol) and N,N-diisopropylethylamine (53 μL, 0.30 mmol). The mixture was stirred at room temperature overnight, and then concentrated in vacuo. The residue was purified by preparative HPLC (100×21.2 mm C18 column, 30-60% MeCN/water[10 mM Et2NH]) and then silica gel column (0-20% MeOH/CH2Cl2) to afford a white foam.
