1.1: toluene-4-sulfonic acid / methanol / 2 h / 25 °C / Inert atmosphere 1.2: 2 h / 25 °C / Inert atmosphere 2.1: sodium azide / N,N-dimethyl-formamide / 48 h / 90 °C / Inert atmosphere 3.1: palladium 10 on activated carbon; hydrogen / methanol / 3 h / 25 °C View Scheme

1: With toluene-4-sulfonic acid in methanol T=25°C; 2 h; Inert atmosphere; 2: With hydrogenchloride in methanol; water T=25°C; 2 h; Inert atmosphere;