...Experiment: Grignard Synthesis of Triphenymethanol Title References: Rosenberg, Robert. (2010). Experimental Organic Chemistry: Howard University Edition. Virginia Beach, VA: Acedemx Publishing Services, Inc. McMurry, John. (2008). Organic Chemistry, 7th Edition. Mason, Ohio: Cengage Learning. Syntheses of triphenylmethanol using the Grignard reagent Phenylmagnesium bromide Abstract A Grignard reaction was demonstrated in order to produce triphenylmethanol from the use of the reagents bromobenzene and phenylmagnesium bromide. This was accomplished by first creating the Grignard Reagent (phenylmagnesium bromide). To do this refluxing of bromobenzene with magnesium and anhydrous ether was done. The Grignard reagent produced was placed in a round bottom flask. Next, a solution of methyl benzoate and ether was slowly mixed into the flask while refluxing was being performed. Upon completion of the reaction, the crystals were isolated using ligroin and vacuum filtration. Analysis of the IR spectra and melting point supported these results. The significance of these findings shows how thoroughly the experiment was carried out. Introduction The Grignard reagent can easily be formed by the reaction of an alkyl halide, in this case bromine, with magnesium metal, in anhydrous diethyl ether. The reaction takes place at the surface of the metal, and the ether plays the role as both the reactant and the solvent. As a result, the Grignard reagent is produced at the surface...
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...Pg(303-309/312-314) 3/11/14 Experiment #36 and 36b Preparation of the Grignard Reagent and Benzoic Acid Purpose- In this experiment we learned to prepare a Grignard reagent, phenyl magnesium bromide, which we then converted to a carboxylic acid. Procedure & Observations- First we started by setting up our apparatus for Grignard reactions. We started by making sure all glassware was completely dried as a Grignard reaction would not occur if water is present. We used a 100ml round bottom flask for our solution and placed it on a hot plate to control the heating process. We then weighed out 0.4920g of magnesium turnings and placed it into the round bottom flask. We also measured out 2.1ml of bromobenzene into a 50ml flask and got a weight of 3.0557g. We then added 10ml of ether to the 2.1ml of bromobenzene and pipetted half into the round bottom flask. The other half was then added to the separatory funnel along with an additional 7ml of ether. From here we began heating the mixture until boiling started to occur. Once the reaction started to begin we got an instant brownish color change. We also ended up using a drop from another group’s reaction to help move along the process. Once this happened we began slowly adding the remaining bromobenzene over a five minute period. Once it had all been added we added an additional 1ml of ether to rinse the funnel. We then heated under gentle reflux till all the magnesium...
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...A Grignard-Like Organic Reaction The Synthesis of 1-phenyl-3-buten-1-ol Introduction The Grignard reaction is an important synthetic process by which a new carbon to carbon bond is formed. Magnesium metal is first reacted with an organic halide forming the Grignard reagent. The Grignard reaction is the addition of an organomagnesium halide (Grignard reagent) to a ketone or aldehyde, to form a tertiary or secondary alcohol, respectively. For example, the reaction with formaldehyde leads to a primary alcohol. Grignard Reagents are also used in the following important reactions: The addition of an excess of a Grignard reagent to an ester or lactone gives a tertiary alcohol in which two alkyl groups are the same, and the addition of a Grignard reagent to a nitrile produces an unsymmetrical ketone via a metalloimine intermediate. A sample Grignard reaction mechanism can be seen in Figure 1 of a Grignard reagent being prepared with an alkyl bromide and later reacted with a formaldehyde to produce a primary alcohol. The purpose of this lab was to form 1-phenyl-3-buten-1-ol using a Grignard reaction. The Grignard reactant was produced from Zinc and Allyl Bromide which was then reacted to Benzaldehyde. The formation of the final product will be confirmed using a Thin Layer Chromatography, TLC, of the product and Benzaldehyde and an IR analysis of the product. Abstract In reactions involving Grignard reagents, it is important to exclude water and air, which rapidly destroy...
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