1: 5-bromoindole-3-carboxaldehyde With sodium tetrahydroborate; formamide in methanol 0.5 h; 2: potassium cyanide in methanol T=100°C; 2.5 h;

tetrabutyl ammonium fluoride in tetrahydrofuran; hexane; water; ethyl acetate; benzene

1: acetic acid / 12 h / 20 °C 2: tetrahydrofuran / 12 h / 20 °C 3: 1.86 g / aq. sodium hydroxide / 12 h / 80 °C View Scheme

in water; N,N-dimethyl-formamide T=70°C; 4 h; Inert atmosphere;

1: tetrahydrofuran / 12 h / 20 °C 2: 1.86 g / aq. sodium hydroxide / 12 h / 80 °C View Scheme

sodium hydroxide T=80°C; 12 h;

in methanol; formamide T=100°C; 2.5 h;

1: With water; potassium hydroxide in methanol T=100°C; 2 h; Inert atmosphere; 2: With hydrogenchloride in water T=0°C; pH=1; Inert atmosphere;

1.1: water; potassium hydroxide / methanol / 2 h / 100 °C / Inert atmosphere 1.2: 0 °C / pH 1 / Inert atmosphere 2.1: hydrogenchloride; thionyl chloride; benzotriazol-1-ol / 4 h / 0 - 25 °C / Inert atmosphere 3.1: iodine; silver trifluoromethanesulfonate / tetrahydrofuran / 0.5 h / 20 °C / Inert atmosphere 4.1: 1,1'-bis-(diphenylphosphino)ferrocene; palladium diacetate; caesium carbonate; copper(l) chloride / N,N-dimethyl-formamide / 2 h / 80 °C / Inert atmosphere View Scheme

potassium hydroxide in tert-butyl alcohol 3 h; Reflux;