HCID 86733872, compound → HCID 22792300, compound

Participants

Reaction Steps

β-tert.-butyl-Nα-tert.-butyloxycarbonyl-L-aspartyl-2,5-dihydro-L-phenylalanine methyl ester (13 g.) is dissolved in trifluoroacetic acid (80 ml.) and the solution kept under nitrogen for one hour. The solvent is concentrated in vacuo and the residue is triturated with ether-hexane until it becomes solid. This material is dissolved in water (ca 30 ml.) neutralized with DEAE sephadex (OH cycle), filtered and the filtrate concentrated in vacuo to a small, volume (ca 5 ml.). The dipeptide ester is crystallized on standing in the refrigerator.

Provenance & Evidence