Privacy & Upon examining the Williamson reaction in Figure 2 in Appendix A, one can see that this reaction involves the introduction of an alkoxide ion to an alkyl halide. Terms If we tried the same reaction with acetaminophen and potassium carbonate, but instead used t-butyl iodide as the alkyl halide, would the reaction still proceed as expected? Is your percent yield within reason of what you would expect? ... One way to synthesize these types of compounds is through a Williamson ether synthesis, which is the reaction … View desktop site, Report Submission - Williamson Ether Synthesis Williamson Ether Synthesis Are you completing this experiment online? Report Submission - Williamson Ether Synthesis Williamson Ether Synthesis Are you completing this experiment online? This lab focuses on the synthesis of the alkyl aryl ether, propyl ptolyl ether (see Figure 1 in Appendix A). What is the purpose of adding 5% sodium hydroxide to the reaction during the work up? Saved Normal ΒΙΙΙΟ XX ELEE fxle ESITIIT TK Also, this lab also aims to teach the effect of a catalyst in a chemical reaction. | 5. List Three Limitations Of The Williamson Ether Synthesis And Explain How Our Choice Of Reagents Circumvents Those Limitations. Lab 1 Report - Diels-Alder Reaction. However, in order for this reaction to occur, both the p-cresol and the propyl iodide must be suspended in a solvent that they are both soluble in. Many new bonds formed make use of this versatile reaction pathway. Williamson Synthesis Lab Report. The phase is heated until the boiling stops, to insure that all impurities are completely boiled out of the mixture. 1 Nucleophilic displacement - Formation of an ether by an SN2 reaction – The Williamson- Ether Synthesis Bond formation by use of an SN2 reaction is very important for organic and biological synthesis. Saved Normal BIU X, X ELE fxle Billilli Te (8pts) 2. Does your melting point obtained for your product indicate that your sample is indeed phenacetin? Terms Theory: Williamson Synthesis is a chemical process developed by Alexander Williamson that is used to synthesize ethers. © 2003-2020 Chegg Inc. All rights reserved. Saved Normal ΒΙΙΙΟ XX ELEE BBIT IT Te (8pts) 3. This ion will behave as nucleophile, and will react with the electrophilic propyl iodide. The remaining product will be propyl p-tolyl ether. Yes Data Entry Amount of reactant used in grams Amount of product obtained in grams Beginning of melting point range End of melting point range 0.147 0.158 129.3 133.0 (22pts) Calculations and Analysis (5pts) Amount of reactant in moles 0.000972 Saved (5pts) Product obtained … In this lab, p-cresol is treated with NaOH to produce a compound that dissociates in water to produce a deprotonated p-cresol ion (see Figure 3 in Appendix A). Finally, the filtered organic phase in then heated again, but this time at (60-65)°C. it. Conversely, p-cresol is soluble in water, yet insoluble in organic solvents. Explain your answer. Centrifugation of fresh milk and Acetic Acid. View desktop site. Ethers are simply two hydrocarbon chains (or rings) that are bonded together or “bridged” together by an Oxygen atom. Synthesis Williamson Report Of Nerolin Ether Lab. Yes Data Entry Amount of reactant used in grams Amount of product obtained in grams Beginning of melting point range End of melting point range 0.147 0.158 129.3 133.0 (22pts) Calculations and Analysis (5pts) Amount of reactant in moles 0.000972 Saved (5pts) Product obtained in moles 0.000882 Saved (5pts) Product theoretical yield 0.174 Saved (5pts) Product percent yield 90.8 Saved | report form. Post Lab Questions: Williamson Ether Synthesis (6 pts) In your lab report answer the following questions and briefly explain your answers: 1. What would you expect to be formed? In order to extract the propyl p-tolyl ether, a series of distillations must be performed. List three limitations of the Williamson ether synthesis and explain how our choice of reagents circumvents those limitations. Privacy Theory: Williamson Synthesis is a chemical process developed by Alexander Williamson that is used to synthesize ethers. 2. Once boiling ceases, the organic phase is further purified by being filtered through which removes any excess in the phase and also through which removes any remaining polar impurities in the phase. Report DMCA. The nucleophilic substitution of halides with alkoxides leads to the desired products. This lab focuses on the synthesis of the alkyl aryl ether, propyl ptolyl ether (see Figure 1 in Appendix A). 6. If there were multiple products comment on finding the mixture melting point of the products. The alkoxide ion is easily produced from the ion’s conjugate acid, which is simply an alcohol or phenol. In the pre-lab preparation you should endeavor to show the main chemical reaction, and study the procedure to see where the deprotonation reaction and actual S N2 reaction are occurring. Suggest an alternative way to synthesize this ether via Williamson ether synthesis to increase the yield of the reaction. Ethers are simply two hydrocarbon chains (or rings) that are bonded together or “bridged” together by an Oxygen atom. & Treatment of tert-butyl chloride with potassium tert-butoxide leads to no significant amounts of di(tert-butyl) ether. Just an S. Williamson who was a professor at University College in London in the latter part of the 1800's Ethyl 2-naphthyl ether. This presents a problem, as propyl iodide is insoluble in water, but soluble in organic solvents. Question: Post Lab Questions: Williamson Ether Synthesis (6 Pts) In Your Lab Report Answer The Following Questions And Briefly Explain Your Answers: 1. This document was uploaded by user and they confirmed that they have the permission to share © 2003-2020 Chegg Inc. All rights reserved. Once the purified organic phase is yielded, it is heated at (35-40)°C to boil out any remaining impurities. The Williamson ether synthesis is an S N 2 reaction in which an alkoxide ion is a nucleophile that displaces a halide ion from an alkyl halide to give an ether. Once the two reagents have reacted within the organic layer, there will still exist some impurities in the mixture. (2pts) Write the equation for the reaction Saved Normal BIU X, X ESIE fx le BEITIT TX (25pts) Post Lab Questions (9pts) 1. Nicholas Johnson Drawer #: U24A TA: Mathew Fields 3-19-2011 Williamson Synthesis Purpose: The purpose of this lab was to become familiar with Williamson Synthesis and, therefore, gain experience with the process of preparing ethers via reactions between alkyl halides and substituted phenoxide anions. 16.6 The Williamson Ether synthesis. 2. By adding diethyl ether to the initial aqueous phase, another organic phase is formed. In order to explain how propyl p-tolyl ether is created in this lab, one must first understand the mechanics of a Williamson reaction. Lab Report. If you are author or own the copyright of this book, please report to us by using this DMCA What additional evidence could you use to determine your product is phenacetin? Heaney, Blackberry Picking - Ioc Points & Analysis, Heaney, Personal Helicon - Ioc Points & Analysis, Heaney, Ancestral Photograph - Ioc Points & Analysis, Heaney, Death Of A Naturalist - Ioc Points & Analysis. What are the best starting materials to use to generate the following ethers? Does your sample appear to be a mixture or pure? Robert J. Ouellette, J. David Rawn, in Organic Chemistry Study Guide, 2015. This is solved with the addition of the phase catalyst, tetrabutylammonium bromide, which acts as a bridge by reacting with the p-cresol anion and carrying it into an organic phase, thus allowing for an electrophile-nucleophile reaction with the propyl cation. Yes or no, explain why. Why does phenacetin remain in the organic layer during work-up, but acetaminophen is extracted to the aqueous layer? This phase is added to the initial organic phase and the mixture of the two organic phases is treated with NaOH and in a series of two distillations to allow for optimal purity. 4. Lab 7 NaoMe + НАС CH3 Br + Br- CH3 HO H3C p-acetamidophenol bromoethane phenacetin Figure 2 Overall reaction to produce phenacetin using Williamson ether synthesis. 5 mL 2.0 M NaOH. Briefly explain your answer. Full Lab Report #8. 3.