F[C:2]1[C:3]([CH3:15])=[C:4]([CH:8]=[CH:9][C:10]=1[S:11]([CH3:14])(=[O:13])=[O:12])[C:5]([OH:7])=[O:6].[CH2:16]([O:18][CH:19]([O:22][CH2:23][CH3:24])[CH2:20][NH2:21])[CH3:17].OS(O)(=O)=O>>[CH2:16]([O:18][CH:19]([O:22][CH2:23][CH3:24])[CH2:20][NH:21][C:2]1[C:3]([CH3:15])=[C:4]([CH:8]=[CH:9][C:10]=1[S:11]([CH3:14])(=[O:13])=[O:12])[C:5]([OH:7])=[O:6])[CH3:17]5.1 g (22 mmol) of 3-fluoro-2-methyl-4-(methylsulfonyl)benzoic acid were dissolved in 30 ml (218 mmol) of aminoacetaldehyde diethyl acetal. The mixture was heated at 120° C. with stirring for 2 days, cooled to RT, acidified with 10% strength H2SO4 and extracted twice with ethyl acetate. The combined organic phases were dried over MgSO4, and the solvent was removed under reduced pressure. This gave 4.0 g of a yellow oil of a purity of 91%.
Wird geladen…