反应详情

温度

70 °C

A 1 L three-necked flask fitted with a mechanical stirrer was charged with 2-phenylaminomethylene-malonic acid diethyl ester (26.3 g, 0.1 mol), polyphosphoric acid (270 g) and phosphoryl chloride (750 g). The mixture was heated to about 70° C. and stirred for 4 h. The mixture was cooled to room temperature, and filtered. The residue was treated with aqueous Na2CO3 solution, filtered, washed with water and dried. 4-Hydroxyquinoline-3-carboxylic acid ethyl ester was obtained as a pale brown solid (15.2 g, 70%). The crude product was used in next step without further purification.

1. customA 1 L three-necked flask fitted with a mechanical stirrer
2. temperatureThe mixture was cooled to room temperature
3. filtrationfiltered
4. additionThe residue was treated with aqueous Na2CO3 solution
5. filtrationfiltered
6. washwashed with water
7. customdried