[C:1]([NH:5][S:6]([C:9]1[O:13][C:12]([C:14]([O:16]C)=O)=[CH:11][CH:10]=1)(=[O:8])=[O:7])([CH3:4])([CH3:3])[CH3:2].[NH:18]1[CH2:21][CH2:20][CH2:19]1>CO>[N:18]1([C:14]([C:12]2[O:13][C:9]([S:6]([NH:5][C:1]([CH3:2])([CH3:3])[CH3:4])(=[O:7])=[O:8])=[CH:10][CH:11]=2)=[O:16])[CH2:21][CH2:20][CH2:19]1To a solution of methyl 5-[(tert-butylamino)sulfonyl]-2-furoate (the product of step i) (2.15 g) in methanol (80 mL) was added azetidine (1.15 mL). After stirring at room temperature for 5 h the mixture was evaporated to dryness in vacuo. The resulting residue was partitioned between EtOAc (50 mL) and H2O (50 mL). The separated organic layer was dried (MgSO4), filtered and evaporated to dryness in vacuo. The resulting crude material was purified by column chromatography (EtOAC as eluent) to give the subtitle compound as a pale yellow oil. Yield: 3 g.
Wird geladen…