1: hydrogenchloride / isopropyl alcohol; water / 18 h / 20 °C 2: sodium hydrogencarbonate / water / 0.5 h / 20 °C View Scheme

1.1: hydrogenchloride / isopropyl alcohol; water / 18 h / 20 °C 2.1: hydrogen bromide; water / 5 h / |Reflux 3.1: triethylamine / tetrahydrofuran; water 4.1: sodium hydride / mineral oil; N,N-dimethyl-formamide / 1 h / 0 - 20 °C 4.2: 1 h 5.1: hydrogenchloride / water; ethanol / 6 h / 20 °C View Scheme

hydrogenchloride in tert-butyl methyl ether; isopropyl alcohol T=20°C; 22 h; Inert atmosphere;

1: hydrogenchloride / isopropyl alcohol; water / 18 h / 20 °C 2: hydrogen bromide; water / 5 h / |Reflux View Scheme

1: hydrogenchloride / isopropyl alcohol; water / 18 h / 20 °C 2: hydrogen bromide; water / 5 h / |Reflux 3: triethylamine / tetrahydrofuran; water View Scheme

1: With hydrogenchloride in water T=60°C; Pictet-Spengler Synthesis; 1 h; Inert atmosphere; 2: With sodium hydroxide in water T=25 - 30°C; Inert atmosphere;

1: ammonium acetate; acetic acid / 12 h / 100 °C 2: lithium aluminium tetrahydride / tetrahydrofuran / 12 h / 0 - 80 °C 3: hydrogenchloride / water / 1 h / 60 °C View Scheme

1: lithium aluminium tetrahydride / tetrahydrofuran / 12 h / 0 - 80 °C 2: hydrogenchloride / water / 1 h / 60 °C View Scheme