[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][N:8]=2)[CH:3]=[C:2]1C=O.[H-].[Na+].[CH3:14][S:15](Cl)(=[O:17])=[O:16].CN([CH:22]=[O:23])C>C(OCC)(=O)C>[CH3:14][S:15]([N:1]1[C:9]2=[N:8][CH:7]=[CH:6][CH:5]=[C:4]2[C:3]([CH:22]=[O:23])=[CH:2]1)(=[O:17])=[O:16]7-Azaindole-2-carboxaldehyde (2.31 g, 15.8 mmoles) from step 1 was dissolved in DMF (50 ml). Sodium hydride (0.76 g, 19 mmol) was added and the reaction was stirred at room temperature for 15 min. Methanesulfonyl chloride (1.8 ml, 24 mmoles) was added and the reaction was stirred for 3 h. The reaction mixture was diluted with ethyl acetate and washed trice with 5% lithium chloride solution, then brine. The organic layer was dried (magnesium sulfate) and concentrated to provide 1-methanesulfonyl-1H-pyrrolo[2,3-b]pyridine-3-carbaldehyde (2.84 g, 80% yield). 1H NMR (CDCl3) δ: 3.71 (3H, s), 7.42 (1H, dd, J=4.7 Hz, 8.1 Hz), 8.30 (1H, s), 8.57 (1H, dd, J=1.7 Hz, 4.7 Hz), 8.63 (1H, dd, J=1.7 Hz, 8.1 Hz), 10.07 (s, 1H).
Wird geladen…