Question

NUCLEOPHILIC DISPLACEMENT- FORMATION OF AN ETHER BY AN SN2 REACTION Bond formation by use of an SN2 reaction is very important for organic and biological synthesis. Many new bonds formed make use of this versatile reaction pathway. In this reaction, one partner is the nucleophile and the other partner is the electrophile. The electrophile will have a leaving group that will be lost in the reaction. In the SN2 reaction that you will be performing, the nucleophile is the phenoxide ion, which is formed from reaction of phenol with sodium hydroxide. The nucleophile will displace the iodide to form butyl naphthyl ether and sodium iodide. Can you think of any possible undesirable side reactions? MI NaOH + Nal + H2O EtOH, Heat phenol chlorbutane butoxybenzene 0.935g/mL 150.22 g/mol EXPERIMENTAL PROCEDURE To a 100 mL round bottom flask (rbf), add 0.56 g (14.0 mmol) of NaOH (about 5 or 6 pellets) and 1.0 g (10.62 mmol) of phenol. Add 20 mL ethanol and a few boiling chips to the flask. Swirl the flask. Reflux the solution for 15 minutes or until all of the solids have dissolved. After 15 minutes, remove the heat source and allow the solution to cool slightly.1 Remove the reflux condenser and add 2.0 mL 1-chlorobutane (17 mmol) to the round bottom flask. Replace the condenser and reflux for an additional hour. Before stopping the reaction, place about 50 mL of water in an ice bath for later use. After 1 hour of refluxing, remove the heat source and carefully pour the contents of the rbf over about 25 g of ice in a 250 ml beaker. Using the water that has been cooling, rinse the rbf and add this to the beaker containing the ice and your product. Swirl the contents of the beaker until all of the ice has melted. Extract the product using petroleum ether 10 mL three times. Separate the petroleum ether layers from the aqueous layers using a separatory funnel. Combine the petroleum ether layers and treat the solutions with calcium carbonate. Filter the solution and wash the filtrate with petroleum ether and combine the dried petroleum ether layers. Boil your petroleum ether off to leave behind butoxybenzene as a liquid. Using the volume or the weight, calculate the percent yield. Make sure the solution has stopped boiling before you remove the reflux condenser.

Please give detailed answers to the pre and post lab questions. Thank you!

Answer 1

Nucleophile is the species that has an electron bair which can be donated to the electrophile on the given reaction, Phenoxide ion is the nucleophile. Structure : J . It is the conjugate base Of shenol 2. Electrophile accepts the electron pair from nucleophile and leaving group attached to it is lost, Here, electrophile is chlor butane n ce -3. Leaving group is-ceo (chloride ion) as the ether product contains no ce atom. Mechanism & Step 1 o formation of phenoxide ion & ttoH ONa + NaOH El Nucleophile + H₂O Nat is spectator ion Nucleophile on chlorbutane of | Step 2: SN 2 to form attack ether FT HAE JA + Nact butoxybenzene (product) Nucleophile lectrophile