The Reaction Of The Acid Anhydride Acid, And Phosphoric Acid Essays

746 Words Oct 6th, 2015 3 Pages
Medicine has evolved greatly, especially in terms of drugs, but one of the basics is aspirin, also referred to as acetylsalicylic acid. There are many different reactions that can be conducted in order to synthesize aspirin. One way being the Fischer esterification, which is a reaction between an alcohol and a carboxylic acid within the presence of a catalyst, synthesizing an ester (Weldegirma, 2014). The catalyst has to be something that will provide the addition of a proton, such as a Lewis acid, in order to provide a more reactive electrophile and speed up the reaction (Fischer Esterification Fischer-Speier Esterification, 2015). Some possibilities for the catalyst are sulfuric acid, tosic acid, and phosphoric acid (James, 2014). For the experiment, the starting materials are salicylic acid, acetic anhydride, and phosphoric acid. The salicylic acid is the compound that contained the alcohol and the acetic anhydride is the compound that contained the carboxylic acid. The main purpose of the acetic anhydride is to donate the acetyl to the salicylic acid, which in the end produces acetylsalicylic acid.Experimental Section Mix salicylic acid, 85% phosphoric acid, acetic anhydride, and a boiling stone in a conical vial. Monitor by TLC, 1:1hexane:EtOAc, followed by heating reaction in steam bath for 5 minutes. Take another TLC, add water to reaction to decompose excess acetic anhydride and cool to room temperature. Place vial in ice bath to for 10 minutes to allow…

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