Diethyl (ethoxymethylene)malonate → Ethyl 4-hydroxy-7-methoxyquinoline-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

m-Anisidine (50 g, 407 mmol) and diethyl ethoxymethylenemalonate (102 g, 407 mmol) were heated at 60° C. for 20 minutes. Diphenyl ether (270 ml) was then added and the temperature was raised to 240° C. over 30 minutes. The ethanol formed distilled off. Heating was maintained at this temperature for 1 hour then the reaction mixture was allowed to cool to 120° C. at which point the reaction mixture was diluted with heptane and allowed to stand overnight at ambient temperature. The brown solid was collected by filtration and washed with methanol and ether to give ethyl 7-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate (45 g, 45%). This reaction was repeated twice.

Provenance & Evidence