O[CH:2]1[C:7]2[CH:8]=[C:9]([S:11]([NH:14][C:15]([CH3:18])([CH3:17])[CH3:16])(=[O:13])=[O:12])[S:10][C:6]=2[S:5](=[O:20])(=[O:19])[N:4]([CH2:21][CH2:22][O:23][CH3:24])[CH2:3]1.C1C=CC(OC(Cl)=S)=CC=1>CN(C)C1C=CN=CC=1.ClCCl>[CH3:24][O:23][CH2:22][CH2:21][N:4]1[CH:3]=[CH:2][C:7]2[CH:8]=[C:9]([S:11]([NH:14][C:15]([CH3:16])([CH3:18])[CH3:17])(=[O:12])=[O:13])[S:10][C:6]=2[S:5]1(=[O:20])=[O:19]The product from Step G (4.11 g, 10.31 mmol) and 4-dimethylaminopyridine (2.52 g, 20.6 mmol) were combined in dichloromethane (50 mL) and the mixture was cooled by means of an ice bath. Phenyl chlorothionoformate (2.1 mL, 15.5 mmol) was added rapidly to the mixture and the cooling bath removed. After three hours the mixture was washed with 2N HCl (15 mL), water (15 mL), saturated aqueous sodium chloride (20 mL), dried (MgSO4) and evaporated to a residue which was purified by column chromatography (silica, hexane/ethyl acetate) to provide the desired product (2.14 g, 39%) as an oil. This oil was heated under vacuum (200° C./5 mm Hg) for approximately 5 minutes (until no more condensate collected) and then purified by column chromatography (silica, hexane/ethyl acetate) to provide the desired product (1.48 g, 97%) which was used in the next step.
Wird geladen…
