A mixture of 4-chloro-6,7-dimethoxy-3-quinolinecarboxamide (0.046 g, 0.35 mmol), methyl 4-amino-2-methylbenzoate acid (0.076 g, 0.46 mmol) and acetic acid (100 μl) in DMF (0.8 ml) was heated at 100° C. for 9 h. After cooling, the mixture was combined with two similar reaction mixtures (starting from 92 and 46 mg 4-chloro-6,7-dimethoxy-3-quinolinecarboxamide respectively) and diluted with water. The mixture was made alkaline with saturated NaHCO3 and the gummy precipitate was collected, washed with water and re-crystallized from methanol to give the title compound (130 mg, 47%).
