[CH2:1]([O:3][C:4](=[O:20])[CH:5]([NH2:19])[CH2:6][CH2:7][C:8](=[O:18])[NH:9][CH:10]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[CH2:11]O)[CH3:2].S(Cl)([Cl:23])=O>ClCCl>[Cl-:23].[Cl:23][CH2:11][CH:10]([NH:9][C:8]([CH2:7][CH2:6][CH:5]([NH3+:19])[C:4]([O:3][CH2:1][CH3:2])=[O:20])=[O:18])[C:13]([O:15][CH2:16][CH3:17])=[O:14]A solution of alcohol 5 (10 g, 35 mmol) in dichloromethane (350 ml) was treated with thionyl chloride (20 mL) and stirred at room temperature under nitrogen overnight. The solvent was removed on a rotary evaporator (bath temperature below 28° C.). Dichloromethane (100 ml) was added and stripped under the same conditions twice. The solid residue was triturated with DCM (100 mL), Heptane (100 mL), and MTBE (100 ml) to give 10 g (84% yield) of pure 6 (LCMS) as a off-white solid.
Wird geladen…