Ibuprofen

  The fourth blog assignment was to find an article containing a synthesis of a common drug and to list any of the Electrophilic Aromatic Substitution reactions in the synthesis.  After thoroughly looking through many websites and journals I finally found an article that had a synthesis for a common drug and that drug is...IBUPROFEN!
  Ibuprofen is an over the counter drug which is used to relieve pain of symptoms of arthritis, fever and other occurrences for pain relief.  It was developed in the 1960s and was discovered by Steward Adams in 1961 and also patented in the same year.  Ibuprofen functions as an inhibitor for an enzyme that directs formation of several mediators of inflammation.
  There are five steps in the synthesis of ibuprofen.  The first step is the electrophilic aromatic substitution step where a Friedel-Crafts acylation occurs. The isobutyl group is a ortho and para director and a benzene activator.  However, the para isomer is formed because there is steric hindrance on the ortho isomer.  The next few steps involve the reduction of the ketone to an alcohol, then conversion of alcohol to a chloro group, then the chloro group is substituted by a cyano group.  The last step involves the hydrolysis of the cyano compound to achieve the final product of ibuprofen.  Listed below is the synthesis:

  The site were the article can be found is:

    http://www.pharmainstitute.in/archives.htm  on the May 2008 issue

Hope this is interesting and allows you to understand electrophilic aromatic substitution in a different way with an actual synthesis of a common everyday drug.