Ethyl p-methylbenzenesulfonate → 1-(1-Ethyl-piperidin-4-yl)-indole

Reaction equation

[NH:1]1[CH2:6][CH2:5][CH:4]([N:7]2[C:15]3[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=3)[CH:9]=[CH:8]2)[CH2:3][CH2:2]1.C(=O)([O-])[O-].[K+].[K+].[C:22]1(C)C=CC(S(OCC)(=O)=O)=C[CH:23]=1>C(O)C>[CH2:22]([N:1]1[CH2:6][CH2:5][CH:4]([N:7]2[C:15]3[C:10](=[CH:11][CH:12]=[CH:13][CH:14]=3)[CH:9]=[CH:8]2)[CH2:3][CH2:2]1)[CH3:23]

Participants

Procedure

To a solution of 1-piperidin-4-yl-1H-indole (0.6 g, 3 mmol) in 5 mL of dry ethanol was added anhydrous potassium carbonate (680 mg, 4.9 mmol). After stirring for 15 minutes at ambient temperature, ethyl p-toluenesulfonate (0.48 mL,4.5 mmol) was added. The reaction was heated under reflux for 24 hours with stirring, quenched with water, extracted with methylene chloride (2×), dried and evaporated to give a residue. The residue was chromatographed on silica gel with toluene/acetone (50:50) to yield 360 mg straw colored material (53% of theory).