4-Carboxyphenylboronic acid, pinacol ester (1.0 eq, 2.01 mmol, 500 mg) and HATU (2.0 eq, 4.02 mmol, 1.53 g) are mixed together in DMF peptide grade (10 mL). Triethylamine (1.2 eq, 2.41 mmol, 0.34 mL) is then added dropwise and the resulting reaction solution is allowed to stir at room temperature for 15 minutes. Isopropylpiperazine (1.2 eq, 2.41 mmol, 0.35 mL) is then added dropwise and the reaction mixture is stirred at room temperature overnight. The reaction mixture is dissolved in EtOAc and washed with water. The organic layer is dried over drying agent MgSO4, filtered and the organic solvent is reduced in vacuo and dried under vacuum at 40° C. to afford the title compound; [M+H]+=359.
