1: 4-(2-N,N-dimethylamino-ethoxy)-1H-boc-indole With lithium diisopropyl amide in tetrahydrofuran; n-heptane; ethylbenzene T=-78°C; 1 h; 2: carbon dioxide in tetrahydrofuran; n-heptane; ethylbenzene T=-78 - 20°C; 2.25 h; 3: With hydrogenchloride in tetrahydrofuran; n-heptane; ethylbenzene; water