反応 #323226

反応方程式

N-chloroacetyl-L-aspartic acid anhydride

methyl L-phenylalaninate

→

aspartame hydrochloride

収率 48.0%

溶媒

dichloroethane

acetic acid

反応条件

後処理

1. 1
   温度the temperature is then raised, in 2 hours, to 15° C.
2. 2
   workup.WAITin 30 minutes
3. 3
   その他to 40° C
4. 4
   その他The dichloroethane is evaporated under vacuum
5. 5
   workup.ADDITION500 ml of methanol and 60 grams of thiourea are added
6. 6
   温度the mixture is refluxed for 3 hours
7. 7
   温度After cooling to 20° C.
8. 8
   workup.ADDITION200 ml of methanol, containing 11% (by weight) of HCl
9. 9
   workup.ADDITIONare added
10. 10
    温度the solution is cooled to 0° C. for 1 hour
11. 11
    ろ過filtered
12. 12
    その他evaporated to dryness in vacuo
13. 13
    その他The residue is crystallized from 600 ml of water containing 70 g of NaCl

実験手順

150 Grams of N-chloroacetyl-L-aspartic acid anhydride are quickly added, at -5° C., to the solution of 140 grams of methyl L-phenylalaninate in 400 ml of dichloroethane plus 200 ml of acetic acid. The mixture is stirred for 1 hour at -5° C.; the temperature is then raised, in 2 hours, to 15° C., then, in 30 minutes, to 40° C. The dichloroethane is evaporated under vacuum; 500 ml of methanol and 60 grams of thiourea are added and the mixture is refluxed for 3 hours. After cooling to 20° C., 200 ml of methanol, containing 11% (by weight) of HCl, are added, the solution is cooled to 0° C. for 1 hour, filtered and evaporated to dryness in vacuo. The residue is crystallized from 600 ml of water containing 70 g of NaCl: a very pure aspartame hydrochloride is obtained, in a 48% yield.

出典