Chemistry 40 Synthesis Of Aspirin (please Edit Schematic Diagram)

Laciste, Jayme Paolo D. Group 3-U2L Chem 40 Exercise 12: Synthesis of Aspirin I: Introduction Aspirin , also known as acetylsalicylic acid is a salicylate drug, often used as an analgesic to relieve minor aches and pains, as an antipyretic to reduce fever, and as an anti-inflammatory medication. Aspirin also has an antiplatelet effect which under normal circumstances binds platelet molecules together to repair damaged blood vessels. This is why aspirin is used in long-term, low doses to prevent heart attacks, strokes, and blood clot formation in people at high risk for developing blood clots. It has also been established that low doses of aspirin may be given immediately after a heart attack to reduce the risk of another heart attack or of the death of cardiac tissue. Salicylic acid is the active ingredient in aspirin that causes pain relief. However this acid is too harsh on the mucous membranes in the mouth, esophagus, and stomach. An acetyl group is added to buffer the effects of the acid. Figure I: Balanced Chemical Equation for the synthesis of aspirin

H

O

O

H O

H

Salicylic acid mp 160oC M.W. 138

+

O

O

O

H2PO4

O

O O

CH3 +

CH3 CH3

O

Acetic Anhydride bp 139oC M.W. 102, d 1.08

Acetylsalicylic acid (aspirin) oC mp 135 -136 M.W. 180

HO

O CH3

Acetic acid

II: Objectives 1. To be introduced to concept of organic analysis 2. To synthesize acetylsalicylic acid from salicylic acid by nucleophilic acyl substitution. 3. To differentiate acetylsalicylic acid from salicylic acid by simple chemical tests. III: Materials and Methods A) Schematic Diagram

B). Set-Up

Figure 2: Heating Set-Up and Suction Filtration Set-Up C). List of Necessary Chemicals and Reagents Name and Structure

Function in the Experiment

Salicylic acid

Reagent

Acetic anhydride

Reagent

Physical Properties; MW (g/mol), MP/BP(0C), Density (g/mL), Apperance 138.10, 160(MP), N.A. Powder –like white solid matter 102.00, 139(BP), 1.08, Clear, colorless homogenous liquid

Hazards

Pulmonary Irritants

Corrosive and Flammable

Precautions

Water

Solvent

Phosporic acid (concentrated)

Catalyst

Diethyl ether

Solvent

Petroleum

Solvent

Ferric Chloride

Differentiating agent

18.02, 100(BP), 1, Clear Homogenous Liquid

Completely Safe

98.00, 158 (BP), 1.69, Clear Colorless Thick Liquid

Extremely Corrosive

74.12, 34 (BP), 0.71, Clear Colorless Liquid

Toxic and Flammable

Flammable

162.2, 306 (BP), 2.90, Blood-like thick, opaque liquid.

Corrosive

IV Data Weight of Watch Glass and Salicylic Acid ……………………. _________ g Weight of Empty Watch Glass…………………………………. _________ g Weight of Salicylic Acid……………………………………….. _________ g Volume of Acetic Anhydride ………………………………….. _________ mL Volume of 85% Phosporic Acid…………. ….………………. _________ drops Time of heating ………………………………………………. __________ min Total amount of water added to product …………………….. ___________mL Weight of Filter Paper plus Product………………………….. ___________g Weight of Dry Filter Paper……………………………………. __________g Weight of Product ……………………………………………. __________ g Percent Yield…………………………………………………. ___________% Theoretical Yield ……………………………………………. ___________g Estimated loss in washing (at 3.3 mg / mL)…………………… __________g Melting point of product……………………………………… __________oC

V Sample Calculations

VI Results and Discussions

VII: References: Borer, L.L. and E. Barry (March, 2000). Synthesis and Characterization of Aspirin and & compostion of Aspirin tablet. Journal of Chemical Education, Volume 77 issue no.3. Retrieved from http://docs.google.com/gview?a=v&q=cache:BVWWlhenVEAJ:employeeweb.cgc.maricopa.edu /k/ri/krishnaswamy/CHM230LLProcedures/Synthesis%2520and%2520Characterization%2520of %2520Aspirin.pdf+characterization+of+aspirin&hl=tl&gl=ph Schneider, R.F. (October, 2006). Syntheis of Aspirin.Che 134, (28). Retrieved from http://www.ic.sunysb.edu/Class/che134/susb/SUSB028.pdf O’ Neal, J.M., et. Al. (2001) The Merck index : an encyclopedia of chemicals, drugs, and biologicals; Whitehouse Station NJ, Merck