反应详情

In 1029 g (8.40 moles) of an aqueous 80% sulfuric acid was dissolved 219.5 g (1.05 mole) of 2-cyanopiperazine sulfate with stirring while keeping the temperature below 40° C. Then, while maintaining the temperature of from 9° C. to 15° C., to the solution was added dropwise 187 g (2.52 moles) of tert-butyl alcohol over a period of 3 hours and further, the mixture was kept at the same temperature for 2.5 hours to complete the reaction. Then, after adding 3 liters of water to the reaction liquid thus obtained, the mixture was neutralized with an aqueous solution of 25% sodium hydroxide until pH thereof became 10. Then, the reaction liquid was extracted twice with one liter of chloroform, the extracts were combined with each other, and chloroform was removed from the mixed extract under reduced pressure to provide 106.8 g (yield 55%) of N-tert-butyl-2-piperazine carboxamide having a melting point of from 151° C. to 152° C.

1. customthe temperature below 40° C
2. temperatureThen, while maintaining the temperature of from 9° C. to 15° C.
3. customthe reaction
4. customto the reaction liquid
5. customthus obtained
6. customThen, the reaction liquid
7. extractionwas extracted twice with one liter of chloroform
8. customwas removed from the mixed
9. extractionextract under reduced pressure