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Expt80 - Exp't 80 Synthesis of Acetylsalicylic Acid...

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Exp’t 80 Synthesis of Acetylsalicylic Acid (Aspirin) from K. L. Williamson, Macroscale and Microscale Organic Experiments, 2nd Ed. 1994, Houghton Mifflin, Boston . p379; revised 10/18/06 Prelab Exercise Write a detailed mechanism of the following acid-catalyzed reaction, the formation of aspirin. OH O OH salicylic acid + O O O acetic anhydride H 3 PO 4 O O OH O + OH O acetylsalicylic acid (aspirin) acetic acid Introduction Aspirin is among the most fascinating and versatile drugs known to medicine, and it is among the oldest. The first known use of an aspirin-like preparation can be traced to ancient Greece and Rome. Salicigen, an extract of willow and poplar bark, has been used as a pain reliever (analgesic) for centuries. In the middle of the last century it was found that salicigen is a glycoside formed from a molecule of salicylic acid and a sugar molecule. Salicylic acid is easily synthesized on a large scale by heating sodium phenoxide with carbon dioxide at 150 ° C under slight pressure (the Kolbe synthesis): O - Na + C O O O H O O OH COO - + 150 o C Sodium salicylate - Unfortunately, however, salicylic acid attacks the mucous membranes of the mouth and esophagus and causes gastric pain that may be worse than the discomfort it was meant to cure. Felix Hoffmann, a chemist for Friedrich Bayer, a German dye company, reasoned that the corrosive nature of salicylic acid could be altered by addition of an acetyl group; and in 1893 the Bayer Company obtained a patent on acetylsalicylic acid, despite the fact that it had been synthesized some 40 years previously by Charles Gerhardt. Bayer coined the name Aspirin for their new product to reflect its acetyl nature and its natural occurrence in the Spiraea plant. Over the years the company has allowed the term aspirin to fall into the public domain so that it is no longer capitalized. In 1904, the head of Bayer, Carl Duisberg, decided to emulate John D. Rockefeller's Standard Oil Company and formed an interessen gemeinschaft (IG, a cartel) of the dye industry (Farbenindustrie). This cartel completely dominated the world dye industry before World War I, and it continued to prosper between the wars, even though some of their assets were seized and sold after World War I. After World War I, an American company, Sterling Drug, bought the
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rights to aspirin. The company's Glenbrook Laboratories division still is the major manufacturer
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This note was uploaded on 03/19/2008 for the course CH 426 taught by Professor Staff during the Spring '08 term at UGA.

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Expt80 - Exp't 80 Synthesis of Acetylsalicylic Acid...

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