Banana Oil Synthesis Report

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aMicroscale Synthesis of Isopentyl Acetate (Banana Oil)
Objective:Carried out the microscale synthesis of isopentyl acetate by direct esterification of acetic acid and isopentyl alcohol. This was an acid catalyzed Fischer esterification. Both extraction and distillation were employed to obtain a pure product. IR spectroscopy and gas chromatography were used to determine purity of the final product. Reagents:

* Compound:| * MW (g/mol):| * MP (°C):| * BP (°C):| * Density (g/mL):| * Properties/ Safety:| * Isopentyl AlcoholC5H12O| * 88.15| * -117.0| * 132.0| * 0.81| * Clear, colorless liquid, disagreeable odor, flammable. Hazardous in case of skin, eye contact and ingestion and inhalation.| * Acetic Acid C2H4O2| * 60.05| * 17.0| * 118.1| * 1.05| * Clear, colorless liquid, pungent odor, flammable. Skin, eye irritant. Inhalation and ingestion hazard.| * Sulfuric Acid H2SO4 * | * 98.08| * 10.0| * 37.0| * 1.84| * Thick, oily, odorless, colorless liquid. Skin, eye, inhalation, ingestion irritant. Overexposure can lead to death. May produce burns.| * Sodium Bicarbonate NaHCO3 * | * 84.00| * 50.0| * 851.0| * 2.20| * Odorless white crystals. Slightly hazardous to skin, eyes, and upon ingestion and inhalation.| * Anhydrous Sodium Sulfate Na2SO4 * | * 142.04| * 884.0| * 1429.0| * 2.66| * Odorless solid, white. Hazardous upon eye and skin contact and ingestion and inhalation| * Isopentyl AcetateC7H14O2 * | * 130.19| * -78.0| * 142| * 0.876| * Colorless liquid, banana odor, flammable. Hazardous upon ingestion and inhalation, and eye and skin hazard| *

Balanced Esterification Equation:
C5H12O + C2H4O2→ C7H1402 + H2O
Esterification of acetic acid and isopentyl alcohol:
+ H2O
Intermediate Reaction:
Extraction of acetic acid by neutralization of acetic acid with sodium bicarbonate:

Procedure: A microscale reflux apparatus was assembled and approximately 1mL of isopentyl alcohol (0.68g), 1.5 mL acetic acid and 1 drop of concentrated sulfuric acid was added to a round bottomed flask. The actual mass of isopentyl alcohol was determined instead of using density because it is more accurate than assuming exactly 1 mL of alcohol was measured. The limiting reagent was calculated and the theoretical yield determined from this result. The solution was refluxed for approximately 30 minutes and then allowed to cool to room temperature. For extraction, 2mL of 5% sodium bicarbonate was added to the flask to react with the acetic acid and convert it to water-soluble sodium acetate and the resulting aqueous layer was removed. The sodium bicarbonate does not react with isopentyl acetate making it ideal for this extraction step. This extraction was repeated and a small portion of anhydrous sodium sulfate was then added to remove any remaining water. There was a loss of product during removal of the liquid due to a spill when the vial was accidentally tipped over. The microscale distillation apparatus was then set up and the compound was heated. The distillation was used to remove the lower boiling point isopentyl alcohol from the product. There was very little product and not much of a temperature increase so the product was removed from the apparatus and cooled to room temperature. It was presumed that most of the alcohol was absent in the product, but IR and GC analysis were used next to verify the purity of the isopentyl acetate. Data and Results:

Total mass of isopentyl alcohol:0.68 g
Determination of limiting reagent based on balanced equation: C5H12O + C2H4O2→ C7H1402 + H2O
Acetic Acid: 1.05g/mL x 1.5 mL x 1mol/60g = 0.26 mol
Isopentyl Alcohol: 0.68 g x 1 mol/88.15 g = .007 mol
The limiting reagent per the above calculation is isopentyl alcohol. Excess acetic acid was used in this experiment to drive the reaction forward. With...
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