potassium carbonate in N,N-dimethyl-formamide T=50°C; 18 h;

1: 5-bromo-1H-indole-2-carboxylic acid ethyl ester With sodium hydride in N,N-dimethyl-formamide 0.25 h; 2: methyl iodide in N,N-dimethyl-formamide T=20°C; 20 h;

1: With sodium hydroxide in 1,4-dioxane; water T=80°C; 2 h; Inert atmosphere; 2: With hydrogenchloride in 1,4-dioxane; water T=23°C; pH=3;