Trifluoroacetic acid → HCID 14180306, compound

Participants

Reaction Steps

t-Butyloxy-D-isoglutamine benzyl ester (3.70 g, 11 mmol) was dissolved in trifluoroacetic acid (20 ml) and the solution was stirred at room temperature for 30 minutes. The solvent was then distilled off, ether was added and the solvent was distilled off again under reduced pressure. Petroleum ether was added to the residue to give crystals, which were dried in the presence of sodium hydroxide in a desiccator, giving D-isoglutamine benzyl ester trifluoroacetate. This product was dissolved in acetonitrile (10 ml) and, under ice-cooling, the solution was neutralized with triethylamine. Then, p-nitrophenyl 10-(2,3-dimethoxy-5-methyl-1,4-benzoquinon-6-yl)decanoate (4.74 g, 10 mmol) was added and the mixture was stirred at room temperature for 16 hours. After completion of the reaction, the solvent was distilled off and the residue was dissolved in ethyl acetate (70 ml). The solution was washed with 5% aqueous solution of sodium bicarbonate (30 ml×3), 1N hydrochloric acid (30 ml×3) and saturated aqueous sodium chloride (30 ml×3) in that order and dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure and the residue was precipitated as a gel from ethyl acetate-ethyl ether. The same procedure was repeated twice to give 10-(2,3-dimethoxy-5-methyl-1,4-benzoquinon-6-yl)decanoyl-D-isoglutamine benzyl ester (3.74 g), melting at 83°-85° C.

Provenance & Evidence