Isopentyl Acetate
Experiment 12: Isopentyl Acetate
19 October 2012
Introduction: The purpose of this experiment is to prepare isopentyl acetate by direct esterification of acetic acid with isopentyl alcohol. After refluxing there is an isolation procedure where excess acetic acid and remaining isopentyl alcohol are easily removed by extraction with sodium bicarbonate and water. The ester is then purified by simple distillation and the IR is then obtained. Techniques and equipment used throughout the experiment include a reflux apparatus, separatory funnel for isolation, vacuum filtration, and simple distillation. The reflux condenser is used to allow thorough distillation of the product with the use of heat to accelerate and stir while vapors fall back into the round bottom flask. Isolation of product is used with the help of the separatory funnel and vacuum filtration. Simple distillation is used to purify product and IR spectroscopy helps compare and test validity of our final product.
Procedure: The experiment is started by assembling a reflux apparatus with a 50 ml round bottom flask containing 5 ml of isopentyl alcohol, 7 ml of acetic acid, and 1 ml of sulfuric acid. It is essential to make sure that the solution is swirled immediately once the sulfuric acid is added. The mixture is then refluxed for 60 – 75 minutes. Once this is done, it is cooled to room temperature. The mixture is then transferred to a separatory funnel. It is first washed with 10 ml of water and when the layers separate, the bottom layer is disposed of. The mixture remaining in the separatory funnel is then washed with 5 ml portions of 5% sodium bicarbonate until the pH of the aqueous layer is basic. It is then mixed with 5 ml of saturated NaCl solution and the layers should once again separate. The product is then dried for 10 – 15 minutes with ~1 g. of anhydrous sodium sulfate and then vacuum filtrated. A simple distillation apparatus is then assembled and the mixture is heated and
19 October 2012
Introduction: The purpose of this experiment is to prepare isopentyl acetate by direct esterification of acetic acid with isopentyl alcohol. After refluxing there is an isolation procedure where excess acetic acid and remaining isopentyl alcohol are easily removed by extraction with sodium bicarbonate and water. The ester is then purified by simple distillation and the IR is then obtained. Techniques and equipment used throughout the experiment include a reflux apparatus, separatory funnel for isolation, vacuum filtration, and simple distillation. The reflux condenser is used to allow thorough distillation of the product with the use of heat to accelerate and stir while vapors fall back into the round bottom flask. Isolation of product is used with the help of the separatory funnel and vacuum filtration. Simple distillation is used to purify product and IR spectroscopy helps compare and test validity of our final product.
Procedure: The experiment is started by assembling a reflux apparatus with a 50 ml round bottom flask containing 5 ml of isopentyl alcohol, 7 ml of acetic acid, and 1 ml of sulfuric acid. It is essential to make sure that the solution is swirled immediately once the sulfuric acid is added. The mixture is then refluxed for 60 – 75 minutes. Once this is done, it is cooled to room temperature. The mixture is then transferred to a separatory funnel. It is first washed with 10 ml of water and when the layers separate, the bottom layer is disposed of. The mixture remaining in the separatory funnel is then washed with 5 ml portions of 5% sodium bicarbonate until the pH of the aqueous layer is basic. It is then mixed with 5 ml of saturated NaCl solution and the layers should once again separate. The product is then dried for 10 – 15 minutes with ~1 g. of anhydrous sodium sulfate and then vacuum filtrated. A simple distillation apparatus is then assembled and the mixture is heated and
References: McMurry, John. Organic Chemistry. 7th ed. Belmont: Thomson Higher Education, 2008. Print. Pavia, Donald L., Gary Lampman, George Kriz, and Randall Engel. Introduction to organic laboratory techniques: a small scale approach. 2ed. Belmont: Brooks/Cole, a division of Thomson Learning, Inc., 2005. Print.