Synthesis of trans-9-(2-Phenylethenyl)anthracene
The purpose of this experiment was to convert carboxyl compounds into alkenes. While this reaction yields both the E and Z isomers, it is preferred over other reactions due to the lack of uncertainty of where the double bond is positioned. Also the stability of an ylide determines which isomer is the major product. 1
50% Aqueous NaOH
Melting Point ( °C)
A white powder of Benzyltriphenylphosphonium chloride (0.255 g, 0.656mmol) and a mustard-yellow colored 9-anthraldehyde (0.143 g, 0.694mmol) were added to an Erlenmeyer flask along with a stir bar and clamped over a stir plate. Dichloromethane (3 mL, 35.3mmol) was added dropwise to rinse the sides of flask so that any solid material drops to the bottom. After the solution was mixed for a few minutes, 50% sodium hydroxide (0.30 mL, 7.5mmol) was also added dropwise and was allowed to stir vigorously for about another 30 minutes. The stir plate is then slowed down to a gentle spin. Water (3mL, 0.16mmol) was then added to the solution and allowed to spin for a few more minutes, and the solution has formed a bilayer. The solution was then poured into a separatory funnel along with additional water (5mL, 0.278mmol). The mixture is then extracted twice with dichloromethane (5ml, 58.87) each time. The organic layer (bottom) was then combined and dried with anhydrous sodium sulfate. The solution is then poured through a Hirsch-funnel. A minimal amount of DCM was used to rinse out the flask and then poured onto the filter paper over the drying agent. The filter paper was removed and used a finger to seal the system to evaporate the remaining DCM...
References: 1. Lindsay, Maria C., and Sean P. Hickey. "Wittig Reaction: Synthesis of trans-9-(2-Phenylethenyl)anthracene."Chem 3018 Organic Chemistry Lab 5. 2nd ed. Vol. 1. John Wiley and Sons, 2014. 19-28. Print.
2. Solomons, T. W. Graham. Organic Chemistry. 11th ed. New York: Wiley, 1992. Print.
3. Loffredo, William M. "Synthesis of Trans-9-(2-phenylethenyl)anthraldehyde: A Witting Reaction." (n.d.): n. pag. Synthesis of Trans-9-(2-phenylethenyl)anthraldehyde: A Witting Reaction. William M Loffredo, 11 Aug. 2004. Web. 2 Mar. 2015.
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