SC CHEM 333 - Williamson Ether Synthesis Post-lab (3 pages)

Previewing page 1 of 3 page document View the full content.
View Full Document

Williamson Ether Synthesis Post-lab



Previewing page 1 of actual document.

View the full content.
View Full Document
Unformatted text preview:

Chemistry 333L 03M Post lab Williamson Ether Synthesis By Cameron Kahn TA James Collie 19 November 2013 Observations After mixing the initial solution comprised of 1 05g 2 naphthol 2 5mL ethanol 1mL of 6M NaOH and 1mL of 1 iodopropane the solution was brown in color before reflux As the solution was heat the solution became cloudier during the middle of the 40 minute reflux period Over the last 15 minutes of the reflux period the solution became clearer Once reflux was completed the solution left a ring of solid around the inside of the 25mL round bottom flask The layer of solid was noted to be somewhat tan in color The solution then went into a 50mL beaker containing 10mL of ice cold water and added ice small amount In the beaker the solution separated into two distinct layers one layer was a dark brown while the other was a lighter tan From there the entire contents of the 50mL beaker were then poured to the separatory funnel where 12mL of diethyl ether was added After swirling the mixture two layers formed The top organic layer was a dark brown color while the bottom aqueous layer was a light tan After removing the aqueous layer and boiling off the ether 3mL of 95 ethanol was added to the remaining milliliters of solution This step yielded a clear slightly colored solution After more than 10 minutes of the solution being introduced to the ice bath little to no crystals formed The melting point observed was 37oC Results Using a revised version of the intended Williamson Ether Synthesis as denoted in the lab manual the results were different The final product was 2 propoxynaphthalene After crystallization the measured mass of the filter paper and the product was 1 004g Subtracting the initial mass of the filter paper 0 182g from the total mass of the product with the filter paper gives the mass of the product The mass of the product was measured to be 0 822g Since we deviated from the lab manual the theoretical product yield cannot be calculated since the product we actually got 2propoxynaphthalene is different from the theoretical product denoted in the lab manual Insufficient information was given to us in order to calculate the theoretical yield of 2propoxynaphthalene and therefore a percent yield cannot be calculated The actual melting point was 37 C while the theoretical melting point was 41 C Comparing the two melting points a 10 81 difference was calculated Calculations Final product Total mass filter paper product mass of filter paper Final product 1 004g 0 182g 0 822g Melting point percent difference oC Theoretical melting point actual melting point x100 actual melting point 41 37 x100 10 81 37 2 Page Conclusion Due to time constraints we did an abbreviated Williamson Ether Synthesis Using the revised procedures we still performed a version of Williamson Ether Synthesis by synthesizing 2propoxynaphthalene from the mixture of 1 05g 2 naphthol 2 5mL ethanol 1mL of 6M NaOH and 1mL of 1 iodopropane The 6M NaOH was the strong base Between the processes of heating the solution and adding ether to separate out the organic product we were able to obtain 0 822g of product No IR analysis was done on our sample A 10 81 difference of melting points were observed and could be explained due to possible impurities such as chemical residues still left on the 25mL round bottom flask or the 50mL beaker from previous labs Also due to not boiling off all the ether some ether still remained in the final product Because ether was still present in the product this would explain why the crystallization of the product did not happen once the solution began to cool in the ice bath All these occurrences were sources of error during the experiment Apart from sources of error the learning outcome from the lab showed the importance of Williamson Ether Synthesis In general Williamson Ether Synthesis is a Sn2 reaction of an alkyl halide reacts with an organic oxide anion to form a new carbon oxide bond Handy To produce many kinds of pharmaceuticals the process of synthesis is needed in order to create a product that compare to the natural product If we were to have done the procedures set on in the lab manual one would synthesize Guaiacol through Williamson Ether Synthesis This product compares to the natural product Guaifenesin which is used in Mucinex Williamson Ether Synthesis is one of many synthesis processes and help chemists create pharmaceuticals including generic medicines IR analysis Due to the absence of the TA to work the IR spectroscopy machine no group in lab was able to obtain an IR graph of their sample to analyze The IR results should show peaks between 1600cm 1 and 1475cm 1 to indicate the two aromatic benzene rings present in the product composition Also sp2 hybridized carbons would be evident and peak at 3100cm 1 while sp3 hybridized carbons would be evident and peak at 2950cm 1 as well Lastly due to the presence of ether as an impurity a peak at around 1150cm 1 should be seen References 1 Ali George Handy and Salman Chemistry 333 334 laboratory Manual Experiemnts in Organic Chemistry Fall 2012 2013 Montgomery Al QDE Press Fall 2012 2 2 Propoxynaphthalene ChemSpider N p n d Web 18 Nov 2013 3 Page


View Full Document

Access the best Study Guides, Lecture Notes and Practice Exams

Loading Unlocking...
Login

Join to view Williamson Ether Synthesis Post-lab and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Williamson Ether Synthesis Post-lab and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?