The Synthesis of Pure (S)- Ibuprofen using a Greener Alternative

Ibuprofen is a fever/pain reducer analgesic. In this four step process the most active enantiomer of ibuprofen, (S)-ibuprofen, is isolated from commercially available tablets. This method has been based off of a previous study but a “greener” approach was taken. Racemic ibuprofen was isolated from six over the counter ibuprofen tablets via extraction. Next the racemic ibuprofen is converted to an acid chloride using SOCl₂ and treated with triethyl amine to form a ketene. The ketene is then reacted with (S)-ethyl lactate to form a mixture of diastereomers which are separated and saponified to yield pure (S)-ibuprofen. To make the reaction more green , ethly chloroformate will also be substituted for thionyl chloride because it's MSDS reactivity rating is 0, whereas thionyl chloride's reactivity rating is 2. The desired product is pure (S)- ibuprofen. (S)- ibuprofen reportedly works in 12 minutes, whereas racemic Ibuprofen takes 36 minutes to show its full effects in the body.