1: With sodium hydroxide; tetrabutylammomium bromide in dichloromethane; water T=10 - 25°C; 2 - 3.5 h; 2: With hydrogenchloride in water; acetone T=20 - 25°C; 0.5 h;

hydrogenchloride in methanol; water T=20°C;

1.1: triethylamine; methyl iodide / acetonitrile / 24 h / 20 - 45 °C / Inert atmosphere 2.1: tetrahydrofuran / 5 h / 10 - 20 °C 3.1: triethylamine / toluene / 12 h / 20 °C 4.1: toluene-4-sulfonic acid / toluene / 12 h / Reflux 5.1: oxalyl dichloride / dichloromethane; N,N-dimethyl-formamide / 2 h / 20 °C / Cooling with ice 6.1: triethylamine / dichloromethane / 1 h / 10 - 20 °C 6.2: pH 1 View Scheme

1.1: triethylamine / toluene / 12 h / 20 °C 2.1: toluene-4-sulfonic acid / toluene / 12 h / Reflux 3.1: oxalyl dichloride / dichloromethane; N,N-dimethyl-formamide / 2 h / 20 °C / Cooling with ice 4.1: triethylamine / dichloromethane / 1 h / 10 - 20 °C 4.2: pH 1 View Scheme

methanol; potassium hydroxide; water T=0 - 5°C; 1 h;