Potassium Iodide → 1-(2-(1,2,3,4-Tetrahydro-9H-pyrido[3,4-b]indol-2-yl)-1-ethyl)-1,3-dihydro-3,3-dimethyl-2H-indol-2-one

Participants

Reaction Conditions

Reaction Steps

2-((3,3-Dimethyl)oxindolyl)ethanol and triethylamine (1.1 equivalent) were dissolved in dichloromethane, cooled to 0° C. under nitrogen with stirring and methanesulfonyl chloride (1 equivalent) was added. The mixture was stirred for 30 minutes, washed with cold dilute hydrochloric acid, dried (MgSO4), filtered and concentrated to dryness. The resulting oil was dissolved in acetonitrile and added to a solution of tetrahydro-β-carboline (1 equivalent) containing potassium carbonate (2.5 equivalent) and potassium iodide (0.1 equivalent). The reaction mixture was heated under reflux for three days under nitrogen. The solvent was removed under reduced pressure and the residue taken up in ethyl acetate. This solution was washed (×2) with water, dried (MgSO4), filtered and concentrated to dry under reduced pressure. Chromatography on silica gel (eluent ethyl acetate/methanol) gave an oil which was taken up in ethyl acetate. Maleic acid (1 equivalent) was added. The solution was refrigerated for 12 hours and the white crystals collected to given 1-(2-(1,2,3,4-tetrahydro-9H-pyrido[3,4-b]indol-2-yl)-1-ethyl)-1,3-dihydro-3,3-dimethyl-2H-indol-2-one as its monomaleate salt, melting point 156°-158° C.

Provenance & Evidence