Trifluoroacetic acid → (3S, 5RS)-3,5-dimethyl-piperazin-2-one

Participants

Reaction Steps

(1S)-[1-(2-oxo-propylcarbamoyl)-ethyl]-carbamic acid tertbutyl ester (5.93 g, 24.3 mmol) is stirred in a solution of 30% trifluoroacetic acid in methylene chloride (100 mL) for three hours. The solvents are removed in vacuo. The residue is dissolved in 50 mL of MeOH and transferred to a par bottle. Palladium on carbon (10%, 1.0 g) is added, and the mixture is hydrogenated under pressure for 24 hours. The catalyst is filtered off; the MeOH is removed in vacuo to afford (3S, 5RS)-3,5-dimethyl-piperazin-2-one which is directly protected with a benzyl carbamate without further purification.

Provenance & Evidence