Tetraphenylcyclopentadienone for Barbara
Tetraphenylcyclopentadienone
Joshua Krank
Principles of Organic Chemistry Laboratory, Department of Chemistry and Biochemistry
North Dakota State University, Fargo, ND 58102
Introduction:
The purpose of this experiment was to synthesize tetraphenylcyclopentadienone using a reaction of dibenzyl ketone (1,3-diphenyl-2-propanone) with benzil in the presence of base. The reaction then proceeded with an aldol condensation reaction.5 This product was obtained using extraction (reflux), recrystallization and vacuum filtration to separate the product from the waste.
Experiment Scheme:
Figure 1: Experiment Reaction5
Figure 2: Step wise reaction mechanism including aldol condensation reaction5
Procedure:
About 1.55-g of benzil, 1.51-g of dibenzylketone and 12-mL of ethanol were placed in a 50-mL round bottom flask. A magnetic stir bar was also placed in the flask. A condenser was attached to the round bottom flask while the flask was placed in a 70oC hot water bath. The mixture was heated until all solids were dissolved. The temperature of the water bath was then heated to 80oC. A pasture pipet was used to add 2.25-mL of ethanolic potassium hydroxide solution downward through the condenser and into the flask. The mixture immediately turned purple. The temperature was then raised to 85oC while being stirred for 15 min. The flask was then removed from the water bath and allowed to cool to room temperature. The flask was then placed in an ice bath for 5 minutes to allow crystallization to complete. Using a Buchner funnel, the crystals were collected and washed in three 4-mL increments of 95% ethanol. The tetraphenylcyclopentadienone was then place in an oven for 15 minutes to dry. The final product was then weighed in order to calculate the percentage yield. Using a small amount of the product, the melting point was also determined. 5
Data:
Name:
Formula:
Molecular Weight: (g/mol)
Amount:
(Collected)
Moles:
Density
MP: (oC)
BP: (oC)
Hazards:
Benzil (s)
C14H10O2
Joshua Krank
Principles of Organic Chemistry Laboratory, Department of Chemistry and Biochemistry
North Dakota State University, Fargo, ND 58102
Introduction:
The purpose of this experiment was to synthesize tetraphenylcyclopentadienone using a reaction of dibenzyl ketone (1,3-diphenyl-2-propanone) with benzil in the presence of base. The reaction then proceeded with an aldol condensation reaction.5 This product was obtained using extraction (reflux), recrystallization and vacuum filtration to separate the product from the waste.
Experiment Scheme:
Figure 1: Experiment Reaction5
Figure 2: Step wise reaction mechanism including aldol condensation reaction5
Procedure:
About 1.55-g of benzil, 1.51-g of dibenzylketone and 12-mL of ethanol were placed in a 50-mL round bottom flask. A magnetic stir bar was also placed in the flask. A condenser was attached to the round bottom flask while the flask was placed in a 70oC hot water bath. The mixture was heated until all solids were dissolved. The temperature of the water bath was then heated to 80oC. A pasture pipet was used to add 2.25-mL of ethanolic potassium hydroxide solution downward through the condenser and into the flask. The mixture immediately turned purple. The temperature was then raised to 85oC while being stirred for 15 min. The flask was then removed from the water bath and allowed to cool to room temperature. The flask was then placed in an ice bath for 5 minutes to allow crystallization to complete. Using a Buchner funnel, the crystals were collected and washed in three 4-mL increments of 95% ethanol. The tetraphenylcyclopentadienone was then place in an oven for 15 minutes to dry. The final product was then weighed in order to calculate the percentage yield. Using a small amount of the product, the melting point was also determined. 5
Data:
Name:
Formula:
Molecular Weight: (g/mol)
Amount:
(Collected)
Moles:
Density
MP: (oC)
BP: (oC)
Hazards:
Benzil (s)
C14H10O2
References: 1) Adapted By Kurt Rublein From Introduction To Organic Laboratory Techniques, A Microscale Approach By D. L. Pavia, G. M. Lampman, G. S. Kriz, And R. G. Engel; 7/1/98, 1. R. The Aldol Reaction of Benzaldehyde and Acetophenone. Exp 't 20. 1990. 2) Aldol Condensation. Aldol Condensation, http://www.organic-chemistry.org/namedreactions/aldol-condensation.shtm (accessed Jan 30, 2015). 3) Material Safety Data Sheet. Chemicals and Laboratory Equipment, http://www.sciencelab.com/msds.php?msdsid=9927187 (accessed 2015). 4) Melting Point Determination. Organic Chemistry at CU Boulder, http://orgchem.colorado.edu/technique/procedures/meltingpt/meltingpt.html (accessed Feb 2, 2015). 5) Pavia; Lampman. Tetraphenylcyclopentadienone. In Organic Chemistry Laboratory Manual; Radke, K.; Stolzenberg, G.; Cengage Learning: Mason, OH, 2009; pp. 53-55. 6) Synthesis of tetraphenylcyclopentadienone. Chemical Forums, http://www.chemicalforums.com/index.php?topic=32718.0 (accessed Feb 2, 2015).