Methyl iodide → 1,4-Dimethylindole

Reaction equation

[CH3:1]I.C(=O)([O-])[O-].[Cs+].[Cs+].[CH3:9][C:10]1[CH:18]=[CH:17][CH:16]=[C:15]2[C:11]=1[CH:12]=[CH:13][NH:14]2>CN(C)C=O>[CH3:1][N:14]1[C:15]2[C:11](=[C:10]([CH3:9])[CH:18]=[CH:17][CH:16]=2)[CH:12]=[CH:13]1

Participants

Procedure

Methyl iodide (28.44 g) and cesium carbonate (82.26 g) were added to a solution of 4-methylindole (22.08 g) in dimethylformamide (200 mL), and the reaction mixture was stirred at room temperature overnight. The reaction mixture was filtered with Celite (trade name), and the filtrate was concentrated under reduced pressure. A saturated aqueous solution of ammonium chloride was added to the obtained residue, and the reaction mixture was extracted with ethyl acetate. The obtained organic layer was washed with water and a saturated salt solution, and concentrated under reduced pressure after drying with anhydrous sodium sulfate. The obtained residue was purified by column chromatography on silica gel (hexane:ethyl acetate=100:0→85:15) to give the title compound (20.83 g) having the following physical data.