1: 1-benzenesulfonyl-5-bromo-1H-pyrrolo[2,3-b]pyridine-3-carboxylic acid methyl ester With lithium diisopropyl amide in tetrahydrofuran T=-78°C; 0.75 h; 2: methyl iodide in tetrahydrofuran T=-78 - 10°C; 3.5 h; 3: With sodium dihydrogenphosphate in tetrahydrofuran T=10 - 20°C;