反应详情

6-Chloroquinaldine (11 g) was dissolved in 15 ml of concentrated sulfuric acid and the solution was ice-cooled. Then, a solution of 7.1 g of potassium nitrate dissolved in 20 ml of concentrated sulfuric acid was added to the solution dropwise, during which operation the reaction temperature was maintained at 10° C. or less. After completion of addition the mixture was agitated at the same temperature as above for 1 hour and then poured onto 200 g of ice. Subsequently, the mixture was rendered alkaline with 10% sodium hydroxide, taking care that the internal temperature should not be raised to above 20° C., thus forming a pale yellow precipitate. The precipitate was collected by filtration, washed with water and recrystallized from ethanol to obtain 12.3 g of 5-nitro-6-chloroquinaldine as pale yellow rhombic crystals having a melting point of 123° to 124° C.

1. temperaturecooled
2. additionwas added to the solution dropwise
3. temperatureduring which operation the reaction temperature was maintained at 10° C. or less
4. additionAfter completion of addition the mixture
5. temperaturebe raised to above 20° C.
6. customthus forming a pale yellow precipitate
7. filtrationThe precipitate was collected by filtration
8. washwashed with water
9. customrecrystallized from ethanol