Ketoprofen → (R)-Ketoprofen

Participants

Reaction Conditions

Reaction Steps

To 468 g of a toluene/(R)-ketoprofen (63% EE) solution containing 94 g of ketoprofen, 671 g of deionized water was added followed by 153 g of 50% NaOH. The phases were mixed and then separated. The aqueous phase was heated to 115° C. (under pressure) and maintained at this temperature for 3 hours. The solution was then cooled to room temperature and 842 g of toluene were added, followed by 103 g of concentrated sulfuric acid. The phases were mixed and the aqueous phase decanted. After decolorization with activated carbon, the organic phase was concentrated to 25% ketoprofen concentration. The concentrate was cooled to 0° C. and kept at this temperature for 5 hours. The solids were filtered, washed with toluene, and dried under vacuum. The weight of the racemized ketoprofen was 62 g and the enantiomeric excess was 1.4% (R)-ketoprofen.

Provenance & Evidence