Experiment 13B
Experiment 13B: Isopentyl Acetate (Banana Oil) Semimicroscale Procedure
Taylor Levin
5.28.14
Chemistry 352- Organic Chemistry Lab
Summer 2014
Purpose:
To prepare isopentyl acetate (banana oil), an ester, from isopentyl alcohol and acetic acid through the Fischer Esterification reaction.
Reactions:
acetic acid + isopentyl alcohol isopentyl acetate + water
C2H4O2 + C5H120 CH3COOCH2CH2CH(CH3)2 + H20
Procedure:
A reflux condenser was assembled using a 25-mL round-bottom flask, hot plate, and aluminum block. It was equipped with a drying tube filled with calcium chloride to control vapors. Approximately 2.5 mL of isopentyl alcohol was massed and placed in the round-bottom flask that contained a stir bar. Using the same graduated cylinder, about 3.5 mL of glacial acetic acid was added to the flask. A calibrated Pasteur pipet was used to add 0.5 mL of concentrated sulfuric acid to the flask and the flask was mixed immediately. The flask was connected to the apparatus and covered with aluminum foil to help retain heat. Using rubber tubing, water was circulated into the lower attachment and out the top attachment and the mixture was brought to a boil. After heating under reflux for 60-75 minutes, the flask was removed from the heating source and left to cool down to room temperature. The reaction mixture from the flask was transferred to a culture tube and 5-mL of water was added. Upon addition of water, careful shaking, and occasional venting, the phases separated and the lower aqueous layer was removed and discarded. Using the same procedure as explained above with water, 2.5 mL of aqueous sodium bicarbonate was added and the lower aqueous layer was again removed and discarded. The same procedure was repeated one last time with 2.5 mL of saturated aqueous sodium chloride and the lower aqueous layer was removed and discarded, leaving behind the crude ester. The crude ester was transferred to
Taylor Levin
5.28.14
Chemistry 352- Organic Chemistry Lab
Summer 2014
Purpose:
To prepare isopentyl acetate (banana oil), an ester, from isopentyl alcohol and acetic acid through the Fischer Esterification reaction.
Reactions:
acetic acid + isopentyl alcohol isopentyl acetate + water
C2H4O2 + C5H120 CH3COOCH2CH2CH(CH3)2 + H20
Procedure:
A reflux condenser was assembled using a 25-mL round-bottom flask, hot plate, and aluminum block. It was equipped with a drying tube filled with calcium chloride to control vapors. Approximately 2.5 mL of isopentyl alcohol was massed and placed in the round-bottom flask that contained a stir bar. Using the same graduated cylinder, about 3.5 mL of glacial acetic acid was added to the flask. A calibrated Pasteur pipet was used to add 0.5 mL of concentrated sulfuric acid to the flask and the flask was mixed immediately. The flask was connected to the apparatus and covered with aluminum foil to help retain heat. Using rubber tubing, water was circulated into the lower attachment and out the top attachment and the mixture was brought to a boil. After heating under reflux for 60-75 minutes, the flask was removed from the heating source and left to cool down to room temperature. The reaction mixture from the flask was transferred to a culture tube and 5-mL of water was added. Upon addition of water, careful shaking, and occasional venting, the phases separated and the lower aqueous layer was removed and discarded. Using the same procedure as explained above with water, 2.5 mL of aqueous sodium bicarbonate was added and the lower aqueous layer was again removed and discarded. The same procedure was repeated one last time with 2.5 mL of saturated aqueous sodium chloride and the lower aqueous layer was removed and discarded, leaving behind the crude ester. The crude ester was transferred to