Sulfuric Acid → 5-((E)-2-(5-(trifluoromethyl)pyridin-3-yl)vinyl)-2,3,4,5-tetrahydro-2,8-dimethyl-1H-pyrido[4,3-b]indole

Participants

Reaction Conditions

Reaction Steps

1-(5-(Trifluoromethyl)pyridin-3-yl)-2-(1,2,3,4-tetrahydro-2,8-dimethylpyrido[4,3-b]indol-5-yl)ethanol (1 equiv.) is refluxed with 25% sulfuric acid for 2 h. The reaction mixture is cooled to 5° C. with an ice-water bath. KOH (15% aq. solution) is added dropwise to the reaction mixture until pH 9-10 is achieved. The reaction mixture is extracted with EtOAc. The combined organic layers are washed with water followed by brine, dried over sodium sulfate and evaporated under vacuum. The crude product is purified by column chromatography over silica gel (100-200 mesh) using a gradient of MeOH-EtOAc (0-10%).

Provenance & Evidence