Triethylamine → cbz-l-prolinamide

Participants

Reaction Steps

To a solution of the resulting (S)-1-carbobenzoxypyrrolidine-2-carboxylic acid (52.2 g:0.21 mole) and triethylamine (21.2 g:0.21 mole) in 525 ml of chloroform was added isobutyl chloroformate (28.7 g:0.21 mole) with stirring under cooling on ice, followed by continuing the stirring for 15 minutes. Dried ammonia gas was bubbled into the mixture for 1 hour and then the mixture was allowed to warm to room temperature and stand overnight. The resulting white precipitate was removed by the filtration, and the filtrate was evaporated under reduced pressure. The residue was dissolved in 200 ml of chloroform and was washed with diluted aqueous hydrochloric acid and water, and dried over magnesium sulfate. Chloroform was distilled off to give 45.8 g of (S)-1-carbobenzoxypyrrolidine-2-carboxamide. Yield: 88%.

Provenance & Evidence