4-Methylmorpholine → 3-Benzyloxycarbonylamino-succinamic acid tert-butyl ester
Reaction equation
[C:1]([O:5][C:6](=[O:23])[CH2:7][C@H:8]([NH:12][C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14])[C:9](O)=[O:10])([CH3:4])([CH3:3])[CH3:2].C[N:25]1CCOCC1.[OH-].[NH4+]>C(Cl)Cl>[C:1]([O:5][C:6](=[O:23])[CH2:7][CH:8]([NH:12][C:13]([O:15][CH2:16][C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1)=[O:14])[C:9]([NH2:25])=[O:10])([CH3:4])([CH3:3])[CH3:2]Participants
Conditions
- Temperature
- -10 °C
Procedure
To a solution of (S)-2-benzyloxycarbonylamino-succinic acid-4-tert-butyl ester (20.0 g, 61.9 mmol) in CH2Cl2 (100 mL) at −10° C. in a salt/ice/water bath was added N-methylmorpholine (8.20 mL, 74.20 mmol). This was followed by dropwise addition of isobutyl chlorofomate (9.63 mL, 74.20 mmol), over 20 min. After 30 min of stirring at −10° C., ammonium hydroxide solution (28% w/w ammonia, 100 mL) was added portionwise over 5 min. The reaction mixture was stirred for another 8 h then followed by removal of the CH2Cl2 in vacuo. The remaining solution was extracted with EtOAc. The combined extracts were washed with 100 mL of each of the following: 5% citric acid, saturated NaHCO3, and brine. Drying and removal of solvents under vacuum gave crude oil which crystallized from Et2O/hexanes mixture. 3-benzyloxycarbonylamino-succinamic acid tert-butyl ester was obtained in 95% yield (19.0 g). MS (APCI) m/z 323.2 (M+1).
Workup
- additionThis was followed by dropwise addition of isobutyl chlorofomate (9.63 mL, 74.20 mmol), over 20 min
- stirringThe reaction mixture was stirred for another 8 h
- customthen followed by removal of the CH2Cl2 in vacuo
- extractionThe remaining solution was extracted with EtOAc
- washThe combined extracts were washed with 100 mL of each of the following: 5% citric acid, saturated NaHCO3, and brine
- customDrying
- customremoval of solvents under vacuum
- customgave crude oil which
- customcrystallized from Et2O/hexanes mixture
Sources & evidence
- ORD record
- ord-5760ac771da1422bbb4623f74fbd72ee
- Source dataset
- uspto-grants-2005_04
- Patent number
- US06875765B2
Reaction notes
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