反应详情

To Dowtherm A (trademark, 30 ml) refluxed under heating was added dimethyl 2-[(4-nitrophenyl)amino]-2-butenedioate (6.32 g, 22.6 mmol) obtained in Example 131, Step 1 over 5 min by small portions. The mixture was refluxed under heating for 25 min and the reaction mixture was cooled to room temperature. The reaction mixture was diluted with ether and the resulting precipitate was filtrated. The obtained crude crystals were suspended in methanol and collected by filtration to give methyl 1,4-dihydro-6-nitro-4-oxo-2-quinolinecarboxylate (4.75 g, 85%, dark brown crystals).

1. temperatureunder heating
2. temperatureThe mixture was refluxed
3. temperatureunder heating for 25 min
4. filtrationthe resulting precipitate was filtrated
5. customThe obtained crude crystals
6. filtrationcollected by filtration