Abstract
Isopentyl acetate was synthesized via a Fischer Esterification and purified via simple distillation. The yield was determined to be 25%. The identity and purity of the product was confirmed by comparison of the measured ultra-micro boiling point (140°C) to the published value (142°C).1
Chemical Equation
Procedure
Isopentyl alcohol (0.787 g, 1.2 mL, 8.93 mmol), acetic acid (1.574 g, 1.5 mL, 26.20 mmol), and sulfuric acid (0.368 g, 0.2 mL, 3.75 mmol) was added to a 5 mL conical vial containing a spinvane. The vial was connected to a water condenser and refluxed for 60 min. The cooled mixture was washed with 5% sodium bicarbonate (2 x 1.0 mL). Sodium sulfate was added to the vial and the crude ester was removed and transferred to a clean vial. The vial was sealed and allowed to stand for 48 hr at rt. The clear liquid was distilled using a Hickman still and hot plate. The purified ester was removed from the still head to yield isopentyl acetate (0.29 g, 25%) and observed as a clear liquid. bp 140°C (lit1 142°C).
Discussion
The sulfuric acid catalyzed Fischer esterification of isopentyl alcohol and acetic acid provided the product isopentyl acetate in 25% yield as a clear liquid. The purity of the product was determined via ultra-micro boiling point analysis. The boiling point of the isopentyl acetate was found to be 140°C. The similarity of the experimental boiling point to the literature value allows for determination of the product identity. The IR spectrum of the isopentyl acetate allows for further confirmation of the product identity, including a lack of contamination by water or isopentyl alcohol, as no peak was observed above 3000 cm-1. The low percent yield could be a result of the initial equilibrium not being shifted to the products strongly enough; a problem that, according to Le Chatlier’s principle, could have been mitigated by increasing the concentration of the reactants.