反应详情

温度

5 °C

A mixture of 4-amino-6-nitroquinazoline (57.0 g) and diethyl ethoxymethylenepropanedioate (130 g) in anhydrous N,N-dimethylformamide (570 ml) was cooled at 5° C. To the reaction mixture was added sodium hydride (65.5% in mineral oil) (13.2 g) in the course of 30 minutes and the mixture was stirred for 1 hour and 40 minutes under ice-cooling. After ammonium chloride (47.2 g) was added to the reaction mixture and stirred for 20 minutes, ice-water (1 liter) was added to the resultant mixture with stirring and allowed to stand to give crystals, which were separated by filtration, washed with water and dried overnight at ambient temperature. The resultant crude crystals were dissolved in chloroform (1.5 liters) under heating. Insoluble materials were filtered off and the filtrate was concentrated under reduced pressure to give crystals, which were dissolved in methanol (300 ml) under heating and allowed to stand at ambient temperature. The resultant crystals were separated by filtration, washed with methanol and dried under reduced pressure to give yellowish crystalline diethyl [(6-nitro-4-quinazolinylamino)methylene]propanedioate (64.9 g).

1. temperaturecooling
2. stirringstirred for 20 minutes
3. stirringwith stirring
4. customto give crystals, which
5. customwere separated by filtration
6. washwashed with water
7. customdried overnight at ambient temperature
8. dissolutionThe resultant crude crystals were dissolved in chloroform (1.5 liters)
9. temperatureunder heating
10. filtrationInsoluble materials were filtered off
11. concentrationthe filtrate was concentrated under reduced pressure
12. customto give crystals, which
13. temperatureunder heating
14. customto stand at ambient temperature
15. customThe resultant crystals were separated by filtration
16. washwashed with methanol
17. customdried under reduced pressure