HCID 15384157, compound → HCID 22859271, compound

Participants

Reaction Steps

(S)-3-[[N-Benzyloxycarbonyl-(L)-phenylalanyl]amino]tetrahydrofuran-2-one (1.5 g) was dissolved in tetrahydrofuran (35 ml) followed by addition of palladium-on-carbon (5%, 0.8 g) and the catalytic hydrogenation was carried out at room temperature and atmospheric pressure. The catalyst was then filtered off and the filtrate was concentrated under reduced pressure. The residue was dissolved in N,N-dimethylformamide (DMF) (35 ml). Then, valproic acid [(C3H7)2CHCOOH](0.622 g) and 1-hydroxybenzotriazole (HOBt) (0.66 g) were added, after which 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (WSCD.HCl) (0.902 g) was added under ice-cooling and the whole mixture was stirred at room temperature for 14 hours. The reaction mixture was then poured into ice-water and extracted with ethyl acetate. The ethyl acetate layer was washed with 10% aqueous citric acid, water, saturated aqueous sodium hydrogen carbonate and saturated aqueous sodium chloride in the order mentioned and dried (MgSO4) and the solvent was distilled off to give (S)-3-[[N-valproyl-(L)-phenylalanyl]amino]tetrahydrofuran-2-one (chemical formula below) (0.55 g, 38%). This product was recrysallized from dichloromethane-ether. Colorless prisms, m.p. 203°-205° C. Optical rotation [α]D -39.3° (c=0.52, CHCl3). ##STR32##

Provenance & Evidence