Ethanol → Dexibuprofen lysine anhydrous

Participants

Reaction Steps

A 500 ml 3 neck flask equipped with mechanical stirrer and thermometer was charged with H2O (42 ml) and L-lysine (37.5 g, 0.25 mole). The mixture was agitated until a solution was obtained. A solution of S(+)-ibuprofen in absolute ethanol (52.6 g, 0.25 mole in 250 ml ethanol) was made up and added to the aqueous lysine over 5 minutes at a temperature ≤35° C. The resulting solution was filtered through a sintered glass funnel (medium frit) to remove any insoluble material. The filtrate was transferred to a 3000 ml 3-neck flask equipped with a mechanical stirrer, addition funnel and thermometer. To this clear solution was added 575 ml of ethanol over 5 minutes at 20°-25° C. The turbid solution was seeded with the L-lysine salt of S(+)-ibuprofen (50 mg) and an additional 400 ml of ethanol was added over 10 minutes. The resulting suspension was aged at 20°-25° C. for 1 hour with agitation, cooled to 0°-5° C. and held for 1 hour. The product was filtered, washed with 5°±5° C. ethanol (2×1 mmol) and dried in vacuo (50° C.) to yield 74 g (84%) of the titled compound. [α]405 =+14.9° C. (C=1, methanol).

Provenance & Evidence