1.1: thionyl chloride / dichloromethane / 3 h / 80 °C 2.1: hydrogenchloride; sodium nitrite; NH4BF4 / water / 0.58 h 2.2: 2 h / 20 °C 3.1: sodium hydroxide; water / methanol / 14 h / 60 °C 3.2: pH 6 View Scheme

diazomethane in tetrahydrofuran; diethyl ether T=0°C; 1 h;

sulfuric acid T=60°C; Inert atmosphere;

1.1: sulfuric acid / 60 °C / |Inert atmosphere 2.1: sodium hydroxide; N-bromosuccinmide / N,N-dimethyl-formamide / 1 h / 20 °C 3.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.33 h / 0 - 20 °C / |Inert atmosphere 3.2: 1 h / 20 °C / |Inert atmosphere 4.1: caesium carbonate / water; toluene / 0.5 h / |Inert atmosphere; |Sealed tube 4.2: 4 h / 120 °C / |Inert atmosphere; |Sealed tube 5.1: lithium hydroxide hydrate / 1,4-dioxane; methanol; water / |Heating 6.1: hydrogen; palladium 10 on activated carbon / methanol; ethyl acetate / 12 h / 20 °C / |Inert atmosphere View Scheme

1: sulfuric acid / 60 °C / |Inert atmosphere 2: sodium hydroxide; N-bromosuccinmide / N,N-dimethyl-formamide / 1 h / 20 °C View Scheme

1: 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine / dichloromethane; N,N-dimethyl-formamide / 24 h / 20 °C 2: tetrahydrofuran / 0 - 20 °C View Scheme

1: 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine / dichloromethane / 0 - 20 °C 2: tetrahydrofuran / 2 h / 0 °C View Scheme

1: 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride; triethylamine / dichloromethane; N,N-dimethyl-formamide / 24 h / 20 °C 2: tetrahydrofuran / 0 - 20 °C 3: 4-(N,N-dimethlyamino)pyridine / dichloromethane / 20 °C View Scheme

1: With sodium hydroxide in 1,4-dioxane; water T=20°C; 16 h; Inert atmosphere; 2: With citric acid in water pH=~ 4;