2,4-Difluoroaniline → HCID 18549168, compound

Participants

Reaction Conditions

Reaction Steps

5.2 g of 2,4-difluoroaniline were added, at a temperature around 20° C., to a solution of 7.7 g of ethyl 3-(2-chloro-6,7,8-trifluoro-3-quinolyl)-2-dimethylaminomethylene-3-oxopropionate in 50 cm3 of trichloromethane and the reaction mixture was left stirring at this temperature for 8 hours. The trichloromethane was concentrated under reduced pressure (20 kPa) at a temperature around 40° C. 120 cm3 of ethanol and 4.5 cm3 of 1,8-diazabicyclo[5.4.0]undec-7-ene were added to the mixture, which was heated at a temperature around 80° C. for approximately 1 hour. After cooling to a temperature around 10° C., the product was filtered off and washed 2 times with 50 cm3 of ethanol and 2 times with 50 cm3 of isopropyl ether. 5 g of ethyl 1-(2,4-difluorophenyl)-7,8,9-trifluoro-4-oxo-1,4-dihydrobenzo[b][1,8]naphthyridine-3-carboxylate were obtained in the form of a yellow solid melting at about 304-306° C., which solid was used without additional purification in the subsequent stages.

Provenance & Evidence