Trifluoroacetic acid → Cyclo(prolylglycyl)

Participants

Reaction Steps

Triethylamine (75 ml, 540 mmol) was added to a solution of the crude trifluoroacetic acid salt of [((S)-pyrrolidine-2-carbonyl)amino]acetic acid methyl ester (15.4 g), which was isolated in the previous step, in methanol (300 ml). The reaction mixture was heated to reflux for 16 hours. It was cooled to room temperature. The solvent was removed in vacuo. The residue was suspended in 2-propanol (150 ml). The precipitation was isolated and dried in vacuo to give 4.38 g of (S)-hexahydropyrrolo[1,2-a]pyrazine-1,4-dione.

Provenance & Evidence