反应详情

温度

140 °C

3.1 g of ethyl ethoxymethylenemalonate was added to 2.7 g of 5,7-dichloro-1,2,3,4-tetrahydroquinoline and the mixture was heated on an oil bath at 110° C. during which time distillation of ethanol was observed. After heating the mixture at the same temperature as above for 30 minutes, 30 g of polyphosphoric acid was added thereto followed by heating at 140° C. for 30 minutes. After completion of the reaction, the reaction mixture was poured into 100 ml of water and the resulting mixture was rendered neutral with a 40% aqueous sodium hydroxide solution to precipitate light brown crystals. Without further purification the crystals were mixed with 100 ml of a 10% aqueous sodium hydroxide solution and the mixture was heat-refluxed for 40 minutes during which time the crystals were dissolved to form a uniform solution. The solution was treated with activated carbon while hot and filtered. The filtrate was allowed to cool and adjusted to a pH of 2 to obtain 2.7 g of 8,10-dichloro-6,7-dihydro-1-oxo-1H,5H-benzo[ij]quinolizine-2-carboxylic acid as light yellow crystals having a melting point of 300° to 304° C.

1. additionwas added
2. customAfter completion of the reaction
3. customto precipitate light brown crystals
4. customWithout further purification the crystals
5. additionwere mixed with 100 ml of a 10% aqueous sodium hydroxide solution
6. temperaturethe mixture was heat-refluxed for 40 minutes during which time the crystals
7. dissolutionwere dissolved
8. customto form a uniform solution
9. additionThe solution was treated with activated carbon while hot and
10. filtrationfiltered
11. temperatureto cool