Ethylenediamine → Piperazine-2-carbonitrile--hydrogen chloride (1/2)

Temperature

30 °C

Into 300 ml of tetrahydrofuran was added 54.1 g (0.9 mole) of ethylenediamine and the mixture was heated to 30° C. To the mixture was added dropwise 52.5 g (0.6 mole) of 2-chloroacrylonitrile over a period of 2 hours with stirring and further stirring was continued for 6 hours. During stirring, the temperature was kept at about 30° C. The reaction mixture formed was cooled to 20° C. and precipitates formed were removed by filtration. After adding 35% hydrochloric acid to the filtrate formed to adjust pH of the mixture to 4, precipitates formed were collected by filtration. The precipitates were dissolved in 20% hydrochloric acid and the solution thus formed was added dropwise to tetrahydrofuran. Precipitates formed were collected by filtration and the solvent attaching the precipitates was removed under reduced pressure to provide 55.2 g (yield 50%) of 2-cyanopiperazine-di-hydrochloride. The analytical values of the product were as follows.

1. stirringfurther stirring
2. stirringDuring stirring
3. customwas kept at about 30° C
4. customThe reaction mixture formed
5. temperaturewas cooled to 20° C.
6. customprecipitates
7. customformed
8. customwere removed by filtration
9. additionAfter adding 35% hydrochloric acid to the filtrate
10. customformed
11. customprecipitates
12. customformed
13. filtrationwere collected by filtration
14. dissolutionThe precipitates were dissolved in 20% hydrochloric acid
15. customthe solution thus formed
16. customPrecipitates
17. customformed
18. filtrationwere collected by filtration
19. customwas removed under reduced pressure

ORD record

ord-f1927b9e9b2442bb910f711e3a488a3f

Source dataset

uspto-grants-1997_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05698697