To a solution of the above carboxylic acid (50 mg) in DMF (1.5 mL) was added EDC (1.5 eq) and HOBT (1.5 eq). The reaction was stirred at room temperature for 15 min, then N-(3-amino-5-tert-butyl-2-methoxy-phenyl)-methanesulfonamide (1.2 eq) was added. The reaction was stirred 12 h, then the DMF was removed in vacuo, the residue was taken up in EtOAc and washed with water, followed by brine. The organics were dried over MgSO4, filtered, and concentrated and the residue was purified by flash chromatography on silica gel (20%-60% EtOAc/hexane) to give the title compound as a white solid (36 mg, 41% yield for two steps).
