Cl[C:2]([O:4][CH2:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1)=[O:3].[NH2:12][CH2:13][CH2:14][CH2:15][C:16]([OH:18])=[O:17].Cl>O1CCOCC1.[OH-].[Na+]>[CH2:5]([O:4][C:2]([NH:12][CH2:13][CH2:14][CH2:15][C:16]([OH:18])=[O:17])=[O:3])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1A solution of 5.16 g (0.103 mmol) of benzyl chloroformate in 100 ml of dry dioxan is added dropwise over a period of 30 minutes to a solution of 10.60 g (0.1 mmol) of 4-aminobutyric acid in 300 ml of 1N sodium hydroxide solution in an ice bath. The reaction mixture is stirred for 30 minutes at room temperature, acidified with 2N hydrochloric acid and extracted with methylene chloride. The organic phase is dried with sodium sulphate and concentrated in vacuo. The 4-benzyloxycarbonylaminobutyric acid obtained is recrystallized from ethyl acetate, methylene chloride and hexane; melting point 61°-62°.
Loading…
