sodium hydroxide in tetrahydrofuran Heating;

1.1: potassium hydroxide / dimethyl sulfoxide / 0.5 h 1.2: 3 h / 20 °C 2.1: acetic acid; nitric acid / 2 h / -10 - 20 °C 3.1: tin; hydrogenchloride / water; ethanol / 0.5 h / |Reflux 4.1: lithium aluminium tetrahydride / tetrahydrofuran / 0.5 h / 0 - 20 °C View Scheme

1: methyl 5-hydroxy-1,2-dimethyl-1H-indole-3-carboxylate With potassium hydroxide in dimethyl sulfoxide 0.5 h; 2: methyl iodide in dimethyl sulfoxide T=20°C; 3 h;