Acetyl chloride → 1-(1H-Pyrrolo[2,3-b]pyridin-3-yl)ethan-1-one

Reaction equation

[NH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][N:8]=2)[CH:3]=[CH:2]1.[Al+3].[Cl-].[Cl-].[Cl-].[C:14](Cl)(=[O:16])[CH3:15]>C(Cl)Cl>[NH:1]1[C:9]2=[N:8][CH:7]=[CH:6][CH:5]=[C:4]2[C:3]([C:14](=[O:16])[CH3:15])=[CH:2]1

Participants

Procedure

(Ref.: J. Org. Chem. 2002, 67, 6226-6227) 7-Azaindole (5 g, 42.3 mmol) is added to a stirred suspension of AlCl3 (22.6 g, 169 mmol) in DCM (300 mL). After stirring at rt for 1 h, acetyl chloride (13.3 g, 169 mmol) is added drop wise and the resulting mixture is stirred for 18 h. The mixture is cooled to 00 C., quenched with MeOH (150 mL) and stirred for 1 h. Silica gel is added to the mixture, the solvents are removed under vacuum, and the residue is purified by silica gel chromatography eluting with 10% MeOH in DCM to afford 1-(1H-pyrrolo[2,3-b]pyridin-3-yl)-ethanone (1.6 g). 1H NMR (300 MHz, CH3OD): δ 8.93(d, 1H), 8.45(s, 2H), 7.50(t, 1H), 3.30(s, 3H).