Methanesulfonic anhydride (184 mg, 1.3 mmol) was added to a solution of Intermediate 386.4 (292 mg, 0.66 mmol) and Et3N (0.30 mL, 2.2 mmol) in CH2Cl2 (5 mL) at 0° C. The mixture was stirred 1 h at 0° C., 1-(di-(tert-butyloxycarbonyl)amino)-6-aminoisoquinoline (475 mg, 1.3 mmol) was added and it was stirred 16 h at ambient temperature. Water (10 mL) was added and the mixture was extracted with EtOAc (3×25 mL). The organics were combined, washed with brine, dried (Na2SO4) and concentrated. Purification by flash chromatography (hexanes, EtOAc) yielded 280 mg of Intermediate 386.5 as a yellow solid. LCMS 783.53 (M+H).
