Methanesulfonic Acid → 6-Chloro-2-(1-ethyl-propyl)-4-phenyl-quinoline-3-carbonitrile

A solution of (2-amino-5-chlorophenyl)(phenyl)methanone (700 mg, 3.02 mmol), 4-ethyl-3-oxo-hexanenitrile (505 mg, 3.63 mmol) and methanesulfonic acid (290 mg, 196 μl, 3.02 mmol) in toluene (40 ml) was stirred for 5 min at room temperature and then heated to reflux using a Dean-Stark-trap to remove water. After 2.5 h the mixture was cooled to room temperature, washed with saturated NaHCO3 solution and water and was evaporated. n-Heptane was added to the remaining residue and the off-white precipitate that formed was filtered off. The precipitate was again dissolved in EtOAc and the solution was washed with saturated NaHCO3 solution and water and was evaporated to yield the title compound (461 mg, 46%) as yellow solid. The filtrate was concentrated and the remaining residue was purified by column chromatography (silica gel, heptane/EtOAc 100:0-0:100) to afford a second batch of the title compound (347 mg, 34%) as yellow solid. MS (ESI): 335.1 (M+H)+.