BOP (133 mg, 0.30 mmol) was added to a mixture containing (5-chloro-2-oxo-1,3-benzoxazol-3(2H)-yl)acetic acid (68 mg, 0.30 mmol), 2-(4-biphenylyl)-N-methyl-1-(1-pyrrolidinyl)-2-propanamine (74 mg, 0.25 mmol) and Et3N (0.042 ml, 0.30 mmol) in DMF (3 ml) and the resulting mixture was stirred at room temperature for 16 h. The crude reaction mixture was purified by preparative HPLC (Xterra PrepRP 30×100 mm, 45 mL/min, A: acetonitrile B: water, PH10, A: 50 to 90% over 12 min, UV detection at 214 nm) to give 17.5 mg (13.9%) as a white solid. MS(ES) m/e 504.4 [M+H]+
