Sodium Hydroxide → HCID 13960198, compound

Participants

Reaction Conditions

Reaction Steps

400 g of polyphosphoric acid was added to 92.66 g (0.40 mole) of the 3-(3-chloro-4-fluoroanilino) butyric acid and this mixture was stirred at 110° C. for 1.5 hours. After being allowed to cool to room temperature, the resulting reaction solution was diluted with 3 liters of water and then adjusted to pH 4-5 with an aqueous sodium hydroxide solution. Then, the solid matter which separated out was extracted with chloroform and this extract was concentrated under reduced pressure. The residue thus obtained was purified by silica gel column chromatography (using chloroform as the developing solvent). The fraction containing the desired product was evaporated to dryness under reduced pressure and the resulting residue was recrystallized from benzene to obtain 7.43 g (8.7% yield) of 5-chloro-6-fluoro-2-methyl-4-oxo-1,2,3, 4-tetrahydroquinoline in the form of yellow crystals. On the other hand, another fraction was worked up in the same manner as above to obtain 8.55 g (10.0% yield) of a structural isomer thereof, or 7-chloro-6-fluoro-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline, in the form of yellow crystals.

Provenance & Evidence