Sodium Hydroxide → HCID 13960198, compound

Participants

Reaction Steps

6.0 g of (+)-3-(2-bromo-5-chloro-4fluoroanilino)butyric acid obtained in Example 5 was added to 60 g of a triethyl phosphate-phosphorus pentoxide mixture (in a weight ratio of 3:2). The resulting mixture was stirred at 80°-90° C. for 15 minutes and then cooled to room temperature. After the addition of 600 ml of water, the resulting mixture was stirred and then extracted twice with 150 ml-portions of chloroform. The extract was washed twice with 200 ml-portions of water, dried and then concentrated under reduced pressure. The residue thus obtained was mixed with 0.1 g of 10% palladium-active carbon, 20 ml of a 1N aqueous solution of sodium hydroxide, and 200 ml of methanol. The resulting mixture was stirred at ordinary temperature and pressure for an hour with hydrogen gas passed therethrough. This reaction mixture was filtered to remove the palladium-active carbon therefrom, the filtrate was concentrated under reduced pressure, and the resulting residue was extracted with chloroform. The extract was concentrated under reduced pressure and the resulting residue was purified by silica gel column chromatography [using n-hexane-ethyl acetate (5:1) as the eluent]. Fractions containing the desired compound were collected and concentrated under reduced pressure to obtain 2.2 g of (-)-5-chloro 6-fluoro-2-methyl-4-oxo-1,2,3,4-tetrahydroquinoline.

Provenance & Evidence