反应详情

温度

24 °C

A solution of 31.5 ml. sulfuric acid in 295 ml. methanol was treated with 66.5 g. L-aspartic acid, and heated at 40-45° C. for 4 hours. The solution was cooled to 24° C., and treated with 28% aqueous ammonia to a pH of 2.5. The mixture was concentrated under vacuum to a thick slurry. The slurry was treated with 750 ml. of 28% aqueous ammonia and 20 ml. water, and stirred at 24° C. for 3.5 hours. The mixture was concentrated under vacuum nearly to dryness, redissolved in 75 ml. water at 55° C., adjusted to pH of 5.4 with excess ammonia, and then cooled to 24° C. The solid was collected by filtration, washed and dried, and finally recrystallized from another 75 ml. water to yield 31.0 g asparagine monohydrate.

1. concentrationThe mixture was concentrated under vacuum to a thick slurry
2. additionThe slurry was treated with 750 ml
3. concentrationThe mixture was concentrated under vacuum nearly to dryness
4. dissolutionredissolved in 75 ml
5. customat 55° C.
6. temperaturecooled to 24° C
7. filtrationThe solid was collected by filtration
8. washwashed
9. customdried
10. customfinally recrystallized from another 75 ml