PREPARATION OF ACETYLSALICYLIC ACID (ASPIRIN)

Aspirin  Used as an analgesic (pain killer) for headaches, toothaches, neuralgia (nerve pain), muscle pain and joint pain.  Also effective as a fever reducer and anti- inflammatory.  Has anticoagulant properties – prevents strokes and heart attacks.

Salicylic Acid  Salicylic acid is the active agent that allows aspirin to have its medicinal properties.  Because salicylic acid contains the functional groups carboxylic acid and phenol, it is too harsh for the mouth, esophagus and stomach lining.  It was made into an ester (acetylsalicylic acid) in 1899 and given the name “aspirin.”

Hydrolysis of Acetylsalicylic Acid Acetylsalicylic acid is hydrolyzed in the small intestine to salicylic acid which can then be absorbed into the blood stream.

Preparation of Aspirin

Testing the Purity of your Product  If any salicylic acid is left unreacted at the end of our experiment, we can detect its presence with 1% iron(III) chloride solution.  The phenol group present in salicylic acid will turn purple.  “Pure” aspirin will not react with iron(III)chloride.

Procedural Tips  Pre-weigh your watch glass to make the calculation of your % yield from the weight of your salicylic acid easier.  Make sure your filtering system is operating without leaks (quiet = good suction)  Be sure to WET your filter paper before pouring your aspirin crystals onto the filter paper in the funnel.

Filtration Setup

Caution!  Do NOT take your aspirin home and use it on yourself.  Be careful not to inhale the salicylic acid when weighing it out at the balances!!!  Question: What is the purpose of putting our dissolved product into ice water and submerging this container into an ice bath?

Potential Health Concerns  Inhalation: irritant, allergen, coughing, drowsiness, damage to the lungs, shortness of breath, labored breathing, loss of appetite and delayed lung edema  Ingestion: corrosive, burning, headaches, gastritis, intoxication, blindness, pain of the mouth and stomach, anorexia, thirst, diarrhea, dizziness, nausea, vomiting, irritability, confusion, low blood pressure, tachycardia, tachypnia, mental disturbances, skin discoloration, circulatory collapse, clammy skin, weak pulse, shallow respirations, coma and death  Skin contact: irritant, delayed burns, redness, cracking, flaking, dermatitis, defatting of the skin, absorption through the skin and white and wrinkled skin later  Eye contact: irritant, corrosion of the eyes with burns, tearing, redness, pain, blurred vision, permanent damage and blindness  Tumorigen, mutagen, teratogen and reproductive effector