Abstract
The purpose of this experiment was to produce isopentyl acetate, banana oil. Acetic acid and isoamyl alcohol were used to synthesize isopentyl acetate. The techniques used for the separation and purification of isopentyl acetate were reflux, liquid-liquid extraction, neutralization and distillation. The identification of isopentyl acetate was based on boiling points and an infrared spectrum. This experiment resulted in a 11.68% yield. The reactants and products of this reaction are in equilibrium, and therefore it was difficult to obtain a 100% yield.
Introduction
An ester is formed through an acid-catalyzed Fischner esterification reaction. This reaction began by refluxing an organic acetic acid with isopentyl alcohol. The ester was further purified by doing a liquid-liquid extraction. Finally, simple distillation was used to separate the compounds. Infrared analysis and boiling points were used to identify the product. The reactant and product are in equilibrium. The reaction was pushed forward by an excess of acid.
The acetic acid contained an electrophilic carbonyl. The isopentyl alcohol acted as the nucleophile. The electrophilic compound attacked the nucleophile and produced both an ester and water. The sulfuric acid was used as a catalyst for this reaction.
Experimental
Acetic acid, concentrated sulfuric acid, and isopentyl alcohol were combined and refluxed for one hour. Upon completion of the reflux, a liquid-liquid extraction was conducted to separate the upper organic ester layer from the aqueous layer. The aqueous layer was discarded. 5% aqueous sodium bicarbonate was added. Another liquid-liquid extraction was done with a weak base ensuring that the pH was above 5. Sodium sulfate was added as a drying agent to remove any trace water from the ester. Simple distillation was performed on the crude ester. The forerun was discarded. Once the ester was collected,
Cited: “Experiment 4-Synthesis of Isopentyl Acetate (An Ester)” http://jan.ucc.nau.edu/~jkn/CHM235L.html. March 03, 2011. Paula Yurkanis Bruice. Organic Chemistry Fifth Edition. Pearson Prentice Hall,2007.435-440.