[CH2:1]([O:3][C:4](=[O:15])[CH:5]=[CH:6][C:7]1[CH:12]=[CH:11][C:10]([NH2:13])=[C:9]([OH:14])[CH:8]=1)[CH3:2].C([O-])(O)=O.[Na+].[Cl:21][CH2:22][C:23](Cl)=[O:24]>C(Cl)(Cl)Cl>[CH2:1]([O:3][C:4](=[O:15])[CH:5]=[CH:6][C:7]1[CH:12]=[CH:11][C:10]([NH:13][C:23](=[O:24])[CH2:22][Cl:21])=[C:9]([OH:14])[CH:8]=1)[CH3:2]To a stirred solution of 11-3 (3.38 g, 16.3 mmol) in CHCl3 (80 mL) was added saturated NaHCO3 (50 mL) and it was then chilled to 0° C. A solution of chloroacetyl chloride (1.94 mL, 24.4 mmol) in CHCl3 (30 mL) was added dropwise to the chilled biphase. Upon addition completion, the reaction was stirred at 0° C. for 1 h. The layers were separated and the aqueous layer was extracted twice with EtOAc. The combined organic layers were washed with brine, dried (Na2SO4) and concentrated to give 11-4 which was used without further purification in the next step.
Wird geladen…