Boron tribromide → HCID 25165679, compound

Participants

Reaction Steps

A dichloromethane solution (5 ml) of 5-fluoro-3-(4-methoxyphenyl)-8-propoxy-1H-quinolin-4-one (249 mg, 0.76 mmol) was cooled to −10° C. in a methanol-ice bath. A 1N boron tribromide (4.08 ml) was added thereto, and the mixture was stirred at room temperature for 6 hours. Ice water and dichloromethane were added to the reaction mixture, and the resultant insoluble matter was collected by filtration. The filtrate was separated and the organic layer was concentrated under reduced pressure. The residue and the substance remaining on the filter were mixed, and the mixture was purified by silica gel column chromatography (dichloromethane:methanol=60:1→25:1). The purified product was concentrated under reduced pressure. Ethyl acetate was added to crystallize the residue. The crystals were collected by filtration, washed with ethyl acetate, and then dried to thereby obtain 220 mg of powdery pale yellow 5-fluoro-3-(4-hydroxyphenyl)-8-propoxy-1H-quinolin-4-one (yield: 92%). Melting point 271-272° C.

Provenance & Evidence