Synthesis of Aspirin
Jeana Greaves Chem3301-112 June 19, 2013 Synthesis of Aspirin from Methyl Salicylate Introduction The synthesis of Aspirin (Acetyl Salicyclic Acid) began with methyl salicylate and sodium hydroxide as the reagent. The polar oxygen accepts the electrons from now positively charged hydrogen. The positively charged sodium disassociates leaving the hydroxide ion with a negative
Scheme 1 shows the mechanisms that were demonstrated during the synthesis of Aspirin.
charge that attracts to the positively charged hydrogen. A more stable structure is formed when the charge on the oxygen moves from being a lone pair to forming a double bond and the ether substituents are removed. In the presence of Hydronium, the negatively charged oxygen shares electrons with a hydrogen from the reagents. This mechanism allows for the formation of Salicylic Acid. When Acetic Anhydride is used as a reagent, the double bond on the ketone is transferred as a charge to the oxygen causing the opposite charges to attract. Once again, the electrophilic oxygen takes the lone pairs between the O-H bonds to form the final product of Aspirin and acetic acid. These mechanisms for this experiment can be seen in Scheme 1. Aspirin is classified as a Non-Steroidal Anti-Inflammatory Drug that is indicated for heart attack, pain, and fever.
Greaves 2
Procedures Part A: Ten milliliters of 6M Sodium Hydroxide was added to two milliliters of methyl salicylate in a test tube. A white, crystal-like precipitate was immediately formed. Even upon shaking, the solution held its structure. The test tube was placed in a water bath containing boiling chips for while swirling the contents occasionally. The test tube was removed after 20 minutes. The precipitate no longer remained; the solution was now a pink liquid. The contents of the test tube were poured into a beaker to cool for approximately five minutes. Once cooled, 25 milliliters of 6M Hydrochloric Acid were slowly poured into the beaker.
Scheme 1 shows the mechanisms that were demonstrated during the synthesis of Aspirin.
charge that attracts to the positively charged hydrogen. A more stable structure is formed when the charge on the oxygen moves from being a lone pair to forming a double bond and the ether substituents are removed. In the presence of Hydronium, the negatively charged oxygen shares electrons with a hydrogen from the reagents. This mechanism allows for the formation of Salicylic Acid. When Acetic Anhydride is used as a reagent, the double bond on the ketone is transferred as a charge to the oxygen causing the opposite charges to attract. Once again, the electrophilic oxygen takes the lone pairs between the O-H bonds to form the final product of Aspirin and acetic acid. These mechanisms for this experiment can be seen in Scheme 1. Aspirin is classified as a Non-Steroidal Anti-Inflammatory Drug that is indicated for heart attack, pain, and fever.
Greaves 2
Procedures Part A: Ten milliliters of 6M Sodium Hydroxide was added to two milliliters of methyl salicylate in a test tube. A white, crystal-like precipitate was immediately formed. Even upon shaking, the solution held its structure. The test tube was placed in a water bath containing boiling chips for while swirling the contents occasionally. The test tube was removed after 20 minutes. The precipitate no longer remained; the solution was now a pink liquid. The contents of the test tube were poured into a beaker to cool for approximately five minutes. Once cooled, 25 milliliters of 6M Hydrochloric Acid were slowly poured into the beaker.