1: ethyl 3-iodo-1H-indole-2-carboxylate With sodium hydride in tetrahydrofuran; mineral oil T=0°C; 0.75 h; Inert atmosphere; 2: benzenesulfonyl chloride in tetrahydrofuran; mineral oil T=0 - 20°C; 16 h; Inert atmosphere;

1: 3-iodo-1-(phenylsulfonyl)-1H-indole With lithium diisopropyl amide in tetrahydrofuran; n-heptane; ethylbenzene T=-60°C; 0.166667 h; 2: C8H8O5 in tetrahydrofuran; n-heptane; ethylbenzene T=-60 - 20°C; 1 h;