Triethylamine → HCID 131733970, compound

Participants

Reaction Steps

A solution of (R)-1-(tert-butoxycarbonyl)-5-oxopyrrolidine-2-carboxylic acid (1.146 g, 5.00 mmol) in dehydrated methylene chloride (25 mL) was cooled to 0° C. under an argon atmosphere and gradually added dropwise isobutyl chloroformate (0.682 g) so that the temperature does not exceed 0° C. Then, triethylamine (0.505 g) was gradually added so that the temperature does not exceed 0° C., followed by stirring 30 minutes, thereby a mixed acid anhydride was prepared in the reaction system. To this reaction mixture was gradually added benzyl hydrazinecarboxylate (0.830 g), after the addition, followed by raising the temperature to room temperature and stirring for 1 hour. This reaction mixture was washed with 0.5M hydrochloric acid and saturated brine, the organic layer was dried over magnesium sulfate and then distilled off under reduced pressure. The resulting residue was subjected to silica gel column chromatography (hexane/ethyl acetate=4/1→0/1→ethyl acetate/methanol=30/1) to afford 1.53 g of the title compound (yield 80.1%).

Provenance & Evidence