Ethanol → HCID 15630311, compound

Participants

Reaction Steps

Ethyl 1-(4-trifluoromethoxyphenyl)-1,4-dihydro-4-oxo-5-difluoromethoxycinnoline-3-carboxylate (200 mg) and a 1N aqueous solution of sodium hydroxide (0.93 ml) were added to a mixed solvent of ethanol (5.5 ml) and water (1.5 ml), and the resultant mixture was stirred at 70° to 80° C. for 3 hours. After being allowed to cool to room temperature, the mixture was diluted with water (50 ml), and washed with ethyl acetate (20 ml). The pH of the water layer was adjusted to pH 2 with concentrated hydrochloric acid to precipitate crystals. The precipitated crystals were collected by filtration, washed with water (5 ml) two times, and dried under reduced pressure to give 120 mg of desired 1-(4-trifluoromethoxyphenyl)-1,4-dihydro-4-oxo-5-difluoromethoxycinnoline-3-carboxylic acid (yield: 64.2%). m.p., 236.5° C.

Provenance & Evidence