Sodium Carbonate → Piperazin-1-yl-acetic acid

Participants

Reaction Steps

A mixture of intermediate (2) (0.019 mol) and Na2CO3 (0.019 mol) in DMF (125 ml) was stirred. Methyl 2-bromo-2-phenylacetate (0.019 mol) was added dropwise. The mixture was stirred at room temperature for 3 hours. The solvent was evaporated. The residue was stirred in DCM and washed with water. The separated organic layer was dried, filtered and the solvent was evaporated. The residue was stirred in DIPE. The precipitate was filtered off, dried and separated by high performance liquid chromatography over Chiralcel OD (eluent:hexane/EtOH 70/30) in its enantiomers. The desired fractions were collected and the solvent was evaporated, yielding 1-piperazineacetic acid, α-phenyl-4-[4-[[[4′-(trifluoromethyl)[1,1′-biphenyl]-2-yl]carbonyl]amino]phenyl]-, methyl ester, (α1A)-(intermediate 33) after crystallisation from 2-propanol, and 1-piperazineacetic acid, α-phenyl-4-[4-[[[4′-(trifluoromethyl)[1,1′-biphenyl]-2-yl]carbonyl]amino]phenyl]-, methyl ester, (α1B)-(intermediate 34) after crystallisation from 2-propanol.

Provenance & Evidence