Synthesis of Isopentyl Acetate
Purpose: To prepare isopentyl acetate from isopentyl alcohol and acetic acid by the Fischer esterification reaction.
Materials: West condenser, 250 mL round bottomed flask, two 250 mL flasks, heating mantle, boiling chips, graduated cylinder, sodium bicarbonate, isopentyl alcohol, glacial acetic acid, concentrated sulfuric acid, separatory funnel Procedure:
1. Place 50 mL of isopentyl alcohol in a 250 mL round bottom flask and add 60 mL of glacial acetic acid. Add the acid very slowly. 2. Swirl the flask and carefully add 8 mL of concentrated sulfuric acid. 3. Attach a reflux condenser, and using a heating mantel, reflux the mixture for 1 hour (do not forget to add boiling stones). Cool to room temperature. 4. Place the reaction mixture in a separatory funnel and add 55 mL of cold water (remember to rinse the reaction flask with 10 mL of cold water and add it to the separatory funnel). Separate the lower aqueous layer. 5. Extract the organic layer (upper layer) with 100 mL of 5% sodium bicarbonate solution twice (test to be certain that the aqueous layer is basic to litmus, otherwise wash again). CAUTION: formation of carbon dioxide which will exert pressure inside the separatory funnel. 6. Extract the organic layer with 50 mL of water. Finally, add 15 mL of saturated aqueous sodium chloride to aid in layer separation (it removes traces of water from the organic layer). Do not shake the solution but simply swirl. Draw off the lower aqueous layer. Pour the top organic layer into an Erlenmeyer flask and dry with 2 grams of anhydrous magnesium sulfate. Observations:
* The isopentyl alcohol and glacial acetic acid turned orange as soon as concentrated sulfuric acid was added. * As time passed while refluxing, the solution gradually became darker to a reddish color. * The final product was a dirty yellow color
* The isopentyl acetate was less dense than water so it was above the...