3′-({4-[(3,5-Dioxo-1,2,4-oxadiazolidin-2-yl)methyl]phenoxy}methyl)-2-methylbiphenyl-4-carboxylic acid (10.8 mg) was dissolved in a THF-methanol [1 ml, 4:1 (v/v)] mixed solution, and the solution was added to 1-ethylpiperidine-3-amine (5.8 mg). DMT-MM (12 mg) was added, followed by overnight stirring at room temperature. Thereafter, chloroform was added to the reaction liquid, and the organic layer was washed with water. The organic layer was concentrated, and the residue was purified by a fractional HPLC (Waters, product name: Waters SunFire™ Prep C18OBD™ (19×100 mm, 5 μm)) to obtain 3′-({4-[(3,5-dioxo-1,2,4-oxadiazolidin-2-yl)methyl]phenoxy}methyl)-N-(1-ethylpiperidin-3-yl)-2-methylbiphenyl-4-carboxamide (3.4 mg).
