Citric Acid → HCID 86641589, compound

Participants

Reaction Conditions

Reaction Steps

10.0 g of (R)-3-t-butoxycarbonylamino-4-(2,4,5-trifluorophenyl)butanoic acid (Chemical Formula 2) produced in the above Example 1 was dissolved in 450 mL of toluene in 2 L flask; 13.0 g of bis(2,2′-benzothiazolyl)disulfide and 10.2 g of triphenylphosphine were added; and then the resulting reaction solution was cooled to 0° C. While stirring the reaction solution, a solution prepared by dissolving 0.8 mL of triethylamine to 20 mL of toluene was added, and then stirred for 5 hours at room temperature. The reaction solution was cooled to 0° C., and then a solution prepared by dissolving 5.6 g of (R)-3-(t-butoxymethyl)piperazine-2-one (Chemical Formula 3) produced in the above Example 2 to 40 mL of toluene, and 2.4 mL of pyridine were slowly added. After 30 minutes, the temperature of the reaction solution was increased to room temperature, and then stirred for further 1 hour. pH of the reaction solution was adjusted to 2.5 using saturated citric acid aqueous solution, and then diluted with 400 mL of ethyl acetate. The reaction solution was washed with brine in twice, and an organic layer was dehydration-concentrated with magnesium sulfate. A residue was purified with column chromatography to obtain 838 mg of a title compound.

Provenance & Evidence