1.1: potassium carbonate / toluene; water / 1 h / 65 °C / |Inert atmosphere 1.2: 2 h / 80 °C / |Inert atmosphere 2.1: urea hydrogen peroxide addition compound; phthalic anhydride / water; ethyl acetate / 45 °C 3.1: trifluoromethanesulfonic anhydride; pyridine / acetonitrile / 1.33 h / 70 - 75 °C 3.2: 2 h / 20 °C 4.1: triethylamine; 4-(N,N-dimethlyamino)pyridine / toluene / 2 h 5.1: hydrogenchloride; water / acetonitrile / 40 - 45 °C View Scheme

1.1: 4-(N,N-dimethlyamino)pyridine; thionyl chloride / tert-butyl methyl ether / 1 h / 15 - 30 °C 2.1: dimethyl sulfoxide / 1 h / 30 - 40 °C 2.2: 0.5 h 3.1: potassium hydroxide; tetra-n-octylammonium bromide / water / 1 h / 70 °C 4.1: sodium hydroxide; water / ethanol / 80 °C 5.1: thionyl chloride / toluene / 0.5 h / 60 °C 6.1: triethylamine; 4-(N,N-dimethlyamino)pyridine / toluene / 2 h 7.1: hydrogenchloride; water / acetonitrile / 40 - 45 °C View Scheme

1.1: dimethyl sulfoxide / 1 h / 30 - 40 °C 1.2: 0.5 h 2.1: potassium hydroxide; tetra-n-octylammonium bromide / water / 1 h / 70 °C 3.1: sodium hydroxide; water / ethanol / 80 °C 4.1: thionyl chloride / toluene / 0.5 h / 60 °C 5.1: triethylamine; 4-(N,N-dimethlyamino)pyridine / toluene / 2 h 6.1: hydrogenchloride; water / acetonitrile / 40 - 45 °C View Scheme