178984-69-5

863785-96-0

178984-69-5

General procedure for the synthesis of methyl 4-chloroquinoline-7-carboxylate from methyl 4-oxo-1,4-dihydroquinoline-7-carboxylate: the residue (0.59 g) was dissolved in N,N-dimethylformamide (20 ml), triethylamine (4 ml) and 10% palladium/carbon (0.59 g) were added. The reaction mixture was stirred overnight under hydrogen atmosphere and at room temperature. After completion of the reaction, the mixture was filtered and the filter cake was washed with chloroform. The solvent was removed by distillation under reduced pressure and the residue was washed with methanol to afford methyl 4-oxo-1,4-dihydroquinoline-7-carboxylate (187 mg, 28% yield). The resulting methyl 4-oxo-1,4-dihydroquinoline-7-carboxylate (650 mg) was suspended in diisopropylethylamine (7 ml), phosphorus trichloride (1.5 ml) was added, and the reaction was stirred at 120 °C for 30 min. After completion of the reaction, water was added to the reaction mixture under ice bath cooling. The aqueous layer was neutralized with aqueous sodium bicarbonate and the organic layer was extracted with ethyl acetate. The ethyl acetate layer was washed with water and dried with anhydrous sodium sulfate. The solvent was removed by distillation under reduced pressure and the residue was purified by column chromatography in acetone-chloroform system to afford methyl 4-chloroquinoline-7-carboxylate (609 mg, 86% yield).