Triethyl Phosphate → Ethyl 1-ethyl-7,8-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of ethyl 7,8-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate (40 g, 144 mmol) and potassium carbonate (29.9 g, 216 mmol) in triethyl phosphate (123 ml, 721 mmol) was stirred at 120° C. for 24 h. LCMS indicated completion of the reaction. The reaction mixture was cooled down to rt and diluted with water, extracted with DCM, dried over sodium sulfate and evaporated in vacuo. The crude material was recrystallized in EtOH, the precipitate was collected by filtration, washed by cold EtOH and dried in air to afford ethyl 1-ethyl-7,8-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate (26 g, 85 mmol, 59.0% yield) as a yellow solid. LCMS: (M+H)+: 306.2.

Provenance & Evidence