反应详情

温度

80 °C

2-Nitro-5-chlorobenzaldehyde diethyl acetal (138 g) was dissolved in 750 ml of dimethylformamide (DMF) and to the solution was added 250 g of anhydrous piperazine and stirred at 80° C. for 4 hours. After removing excessive piperazine and DMF by evaporation under reduced pressure, and a dilute aqueous sodium hydroxide solution was added to the residue to dissolve. Then, the solution was extracted with methylene chloride. The methylene chloride layer was washed with water and dried over sodium sulfate followed by removal of the solvent by distillation. To the residue was added 850 ml of isopropyl alcohol to dissolve, and to the solution was added 65 ml of concentrated hydrochoric acid and heated under reflux for 1 hour. After cooling, the crystals which precipitated were collected by filtration to give 93 g of 2-nitro-5-piperazinylbenzaldehyde hydrochloride, m.p. 195°-201° C.

1. customAfter removing excessive piperazine and DMF
2. customby evaporation under reduced pressure
3. additiona dilute aqueous sodium hydroxide solution was added to the residue
4. dissolutionto dissolve
5. extractionThen, the solution was extracted with methylene chloride
6. washThe methylene chloride layer was washed with water
7. dry with materialdried over sodium sulfate
8. customfollowed by removal of the solvent by distillation
9. additionTo the residue was added 850 ml of isopropyl alcohol
10. dissolutionto dissolve
11. additionto the solution was added 65 ml of concentrated hydrochoric acid
12. temperatureheated
13. temperatureunder reflux for 1 hour
14. temperatureAfter cooling
15. customthe crystals which precipitated
16. filtrationwere collected by filtration