Hydrochloric Acid → 2,3-dihydro-1H-indol-7-yl(phenyl)methanone

Participants

Reaction Conditions

Reaction Steps

To a solution of 357 mg (3 mmol) of indoline 3 dissolved in 10 ml of 1,2-dichloroethane are added 0.5 ml (3×1.2 mmol) of triethylamine, 0.44 ml (3×1.2 mmol) of boron trifluoride ether adduct, and 0.43 ml (3×1.2 mmol) of silicon tetrachloride, and the mixture is heated under reflux with stirring for 2 hours. The reaction mixture is evaporated; 0.62 ml (3×2 mmol) of benzonitrile is added to the residue and the mixture is heated at 160° C. with stirring for 5 hours and then cooled. The mixture is mixed with 5 ml of 6N hydrochloric acid and heated at 100° C. for 20 minutes. The reaction mixture is basified with potassium carbonate and extracted with dichloromethane. The organic layer is washed with water, dried over anhydrous potassium carbonate, and concentrated. The residue is chromatographed on a column of 4.6 g of silica-gel and eluted with dichloromethane. The eluate from dichloromethane is concentrated. The residue is recrystallized from ether-petroleum either to give 555 mg of 7-benzoylindoline 7 as crystals.

Provenance & Evidence