Purpose To be able to convert the analgesic drug acetaminophen to a less potent analgesic, phenacetin through Sn2 mechanism.

Theory Phenacetin is an older analgesic, which is no longer sold in USA because of the toxic effects. Acetaminophen forms from the natural degradation of phenacetin. William ether synthesis is an organic reaction that forms an ether from an organohalide and an alcohol. The use of anions derived from alcohols or phenols (alkoxides or phenoxides) as nucleophiles in Sn2 alkylation reactions is an important organic reaction.

Reaction

Methods/Procedures
1. Crush one half of an acetaminophen tablet using mortar and pestle then adding the powder to a GlassChem vessel.
2. Add 1.30 g of K2CO3 and 8 mL of 2-butanone.
3. Add 1.2 mL of ethyl iodide and immediately hand the vessel to your TA.
4. The mixture will be heated at 75 degree C for 5 min using CEM Mars 6 laboratory microwave.
5. After the heating period, the solution will be allowed to cool to 50 degree C in the microwave. When TA return the vessel then add solution in a beaker, continue cooling in an ice bath, and then gravity filter the solution into a clean separatory funnel.
6. Wash the residue in the vessel and on the filter paper with 20 mL of diethyl ether to carry any additional product into the separatory funnel. Place the residue and filter paper into a labeled baggie found in Used Chemical Hood. Return vessel.
7. Add 20 mL of 1 M NaOH to the solution in separatory funnel and mix.
8. Remove the aqueous layer and pace it into Used Acid/Base container found in the Used Chemical Hood.
9. Wash the remaining ether layer with two 10 mL portions of water. The combined aqueous layers can be placed in the sink.
10. Place the washed ether layer in a 125 mL Erlenmeyer flask and dry the solution with a small amount of sodium sulfate. Agitate the solution with sodium sulfate for about 5 minutes. Place the now dry ether solution in a clean 25 mL RB flask and Rotovap to remove the ether. Place a small piece of paper between the ground glass of the RB flask and the ground glass of the Rotovap to aid in evaporating the 2-butanone.
11. For recrystallization, place enough hot water in the RB flask to dissolve the crystals and then transfer the solution to a small beaker so you can easily isolate the crystals. Cool the solution on the lab bench to room temperature and then in an ice bath to induce crystallization.
12. Collect the product by vacuum filtration using Hirsch funnel with a 25 mL filtering flask, wash with ice-cold water and dry.
13. Record the mass of recrystallization phenacetin and take a melting point of the product.
14. From HNMR and CNMR of phenacetin provided, identify the various protons and carbons on the structure.

Cautions: 2-Butanone is flammable and an irritant. Ethyl iodide is corrosive to the skin and extremely dangerous if splashed in the eyes. Remove with copious amounts of water.

Citation: Hartung, Richard. Chemistry 253 Organic Chemistry I. N.p.: n.p., 2015. Print.

Observations/Results The first Melting