Malonate Ion → Ethyl 7-fluoro-5,6-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate

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Reaction Conditions

Reaction Steps

To Dowtherm (150 mL) heated at 250° C. was added diethyl 2-(((3-fluoro-4,5-dimethoxyphenyl)amino)methylene)malonate (30 g, 87 mmol). The mixture was stirred at 250° C. for 30 min. LCMS indicated completion of the reaction. The reaction mixture was allowed to cool a bit and was then added to cold hexane, the precipitates were collected by filtration, washed with hexane and then allowed to dry in the air. Similar scale reactions were repeated several times. From a total amount of the malonate (148 g, 434 mmol), a mixture of ethyl 5-fluoro-6,7-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate and ethyl 7-fluoro-5,6-dimethoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate was obtained as brown solid without further purification (103 g, 349 mmol, 80% yield). LCMS: (M+H)+: 296.1.

Provenance & Evidence