Ethanol → Pipecolic acid, (-)-

Participants

Reaction Conditions

Reaction Steps

To a mixture of about 600 mL of 95% ethanol and 200 mL water at 80° C. was added about 40 g of DL-pipecolic acid followed by the addition of 49 g of D-tartaric acid. The reaction mixture was stirred at 80° C. for about an hour to get a clear solution. The solution was allowed to stand at about 25° C. for about 48 hrs and the solid precipitated was filtered. The filtrate was reduced to 260 mL by evaporation and allowed to stand at about 25° C. for 24 h. At the end of that period, more solid had precipitated out and was removed by filtration The filtrate was evaporated to dryness and the residue was dissolved in 1 L water. The water solution recovered was then treated with Amberlite Ion-Exchange resin IR-120 H+ form (Hydrous form) to remove the tartaric acid followed by 10% NH4OH solution treatment of the resin to give L-pipecolic acid of optical purity of about 85-90%. After drying 22 g of a solid was obtained.

Provenance & Evidence