[Cl:1][CH2:2][C:3]([NH:5][C:6]1[C:15]2[C:10](=[CH:11][CH:12]=[C:13]([OH:16])[CH:14]=2)[CH:9]=[CH:8][CH:7]=1)=[O:4].C(N(CC)CC)C.[CH3:24][S:25](Cl)(=[O:27])=[O:26]>CN(C=O)C>[Cl:1][CH2:2][C:3]([NH:5][C:6]1[CH:7]=[CH:8][CH:9]=[C:10]2[C:15]=1[CH:14]=[C:13]([O:16][S:25]([CH3:24])(=[O:27])=[O:26])[CH:12]=[CH:11]2)=[O:4]To a solution of the crude alcohol from Step A (50.3 mmol) in 150 mL of DMF at 0° C. was added triethylamine (15.0 mL, 108 mmol), followed by dropwise addition of methanesulfonyl chloride (6.0 mL, 77.5 mmol). After 16 hours, additional portions of triethylamine (7.0 mL, 50 mmol) and methanesulfonyl chloride (3.0 mL, 39 mmol) were added. After 4 hours, the solution was concentrated in vacuo and partitioned between EtOAc and saturated NH4Cl solution. The organic layer was extracted with saturated NaHCO3 solution and brine, dried (Na2SO4), filtered, and concentrated in vacuo to provide a dark purple solid.
Loading…
