1: ethyl 3-[3-(2-ethoxy-2-oxoethyl)-1H-indol-2-yl]propanoate With sodium hydride in N,N-dimethyl-formamide; mineral oil T=5°C; 0.266667 h; Inert atmosphere; 2: methyl iodide in N,N-dimethyl-formamide; mineral oil T=5 - 20°C; 0.5 h; Inert atmosphere;

1.1: toluene / 16 h / Reflux; Inert atmosphere 2.1: sulfuric acid / 2.5 h / 90 - 92 °C / Inert atmosphere 2.2: 5 - 18 °C / pH 7 / Inert atmosphere 3.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.27 h / 5 °C / Inert atmosphere 3.2: 0.5 h / 5 - 20 °C / Inert atmosphere View Scheme

1.1: sulfuric acid / 2.5 h / 90 - 92 °C / Inert atmosphere 1.2: 5 - 18 °C / pH 7 / Inert atmosphere 2.1: sodium hydride / N,N-dimethyl-formamide; mineral oil / 0.27 h / 5 °C / Inert atmosphere 2.2: 0.5 h / 5 - 20 °C / Inert atmosphere View Scheme