A mixture of 2-amino-2'-chloro-3,5-dimethylbenzophenone (2.59 g), methyl 3,3-dimethoxypropionate (3.7 g), p-toluenesulfonic acid hydrate (0.19 g) and benzene (30 ml) was refluxed for 16 hrs., with removal of water by a Dien-Stark apparatus. The mixture was distilled to remove the solvent, and the residue was purified by a column chromatography on silica gel to give methyl 4-(2-chlorophenyl)-6,8-dimethyl-3-quinolinecarboxylate as crystals (1.90 g, 58.5%), which was recrystallized from isopropyl ether as colorless prisms. m.p. 117°-118° C.
