Organic Chemistry Lab I (CHEM 237) Experiment 10: Phase Transfer Catalysis 100% Correct

Organic Chemistry Lab I (CHEM 237) Experiment 10: Phase Transfer Catalysis 100% Correct List the procedural steps, from start to finish, that are required to convert 2-naphthol and allyl bromide into allyl 2-naphthyl ether. The reaction is performed on a small scale by mixing the alcohol, the haloalkane, and the phase transfer catalyst in a conical vial. Sodium hydoxide (base) is added to initiate the reaction. The reaction flask is covered and stirred to conduct reaction to prevent evaporation of the solvent. The progress of the reaction is monitored by TLC so that no time is wasted. The reaction solution is then dried over calcium chloride to remove any remaining water. The product is purified by column chromatography and collected by evaporation. Match the procedural step to its purpose by dragging each step in the written procedure for the reaction of 2-naphthol with allyl bromide and a phase transfer catalyst in strong base into the appropriate box. The Williamson ether synthesis between 2-naphthol and allyl bromide in the presence of strong base and benzyltriphenylammonium chloride as a phase transfer catalyst in dichloromethane solution is known to proceed in reasonable yield. Why will the reaction fail to work if the solvent is switched to ethanol while retaining the same reactants, phase transfer catalyst, and base? Because the base would deprotonate ethanol and create a second nucleophile. The Williamson ether synthesis between 2-naphthol and allyl bromide in the presence of strong base and benzyltriphenylammonium chloride as a phase transfer catalyst in dichloromethane solution is known to proceed in reasonable yield. The need for a phase transfer catalyst would be removed if a polar aprotic solvent such as DMSO were used as a reaction solvent. Why is DMSO not used as a solvent for this reaction? Because of risks associated with toxicity. In the reaction to produce allyl 2-naphthyl ether, 2-naphthol is first reacted with aqueous sodium hydroxide to make sodium 2-naphtholate, which then goes on to react with allyl bromide and benzyltributylammonium chloride phase transfer catalyst, with dichloromethane as a solvent. Note: the boxes in the diagram represent the layers inside the reaction flask part-way to completion. Place the labels in the appropriate box. (If a molecule has significant solubility in both layers, it may be used more than once). A Williamson ether synthesis between 2-naphthol and allyl bromide is performed in the presence of a phase transfer catalyst and strong base in dichloromethane solution. The reaction mix contains: unreacted allyl bromide, unreacted 2-naphthol, benzyltributylammonium chloride, allyl naphthyl ether, and dichloromethane. The reaction mix is passed through a silica gel mini column. Drag and drop the components of the mixture that elute from the column into the blue box next to the sample vial. A Williamson ether synthesis is shown below. 2-naphthol in the presence of sodium hydroxide undergoes a deprotonation to give the alkoxide shown below. Benzyl bromide is then added and undergoes a nucleophilic substitution by SN2 mechanism. Add curved arrows to demonstrate the SN2 substitution described. Sodium hydroxide can cause severe damage to skin and eyes. True Lachrymators like allyl bromide are specifically dangerous because of their explosion hazard. False The primary risk associated with dichloromethane is its flammability. False Unused allyl bromide can be disposed of in the aqueous waste. False Gloves and goggles are not required when handling sodium hydroxide. False