1. Main reaction sequence including side reaction products: 2. 3 Sentence Summary of the Experiment: The OH group on the benzene ring in salicyclic acid reacts with acetic anhydride to form an ester functional group. Thus the formation of acetylsalicyclic acid (aspirin) is referred to as an esterification reaction, which requires the presence of H+ (H2SO4 in our case). The technique used to purify the aspirin content is called crystallization, which consists in allowing the reaction to cool, decreasing the solubility of acetylsalicyclic acid and allowing it to crystalize.
To purify the product even more a recrystallization procedure will be performed. Since salicyclic acid is considered a phenol, a Ferric Chloride test (shows the presence of phenols by changing color from orange to different concentrations of purple, the darker it is the more concentration of phenol is present. ) will be performed at the beginning of the experiment and also after each crystallization in order to demonstrate the presence of phenols in the results and thus the purity of the product. A melting point range will also be performed in order to verify the purity of the product. 3. Reagents needed to start with mole calculations:
– 0. 0145 mol of Salicyclic Acid – 0. 05 mol of Acetic Anhydride – 5 drops of conc. H2SO4 approximately 0. 005 mol 4. Apparatus needed to start: – 125ml Erlenmeyer Flask – 50 Co Water Bath – Vacuum filter and drier – Hot plate – Ice Bat Check out: Work area/bench clean:____________________________ GTA or instructor signature:________________________ Check out: Work area/bench clean:____________________________ GTA or instructor signature:________________________ 5. Safety Concerns – H2SO4 is extremely corrosive – Acetic Anhydride is a Lachrymator (irritates eyes) – Ethyl Acetate is flammable (fire hazard).