Triphenylethanol Synthesis Lab Report

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Abstract: In this experiment, triphenylmethanol was synthesized in two steps. First, the bromobenzene was reacted with dry magnesium turnings to produce Grignard reagent. Second, the Grignard reagent was reacted with methyl benzoate and concentrated sulfuric acid to produce an alcohol. The end result of the experiment was not very successful because only 17% yield of final product triphenylmethanol was recovered, and the final product was impure based on the melting point and the IR spectrum results. Many sources of error were responsible for recovering a small amount of product. Introduction: The carbon-carbon bond formation is an important tool in organic chemistry to construct the simple as well as an organic compound. There are several …show more content…

The apparatus for the addition reaction under reflux was assembled. Magnesium (1 g) was weighted on a paper, and a few pieces of magnesium were crushed in order to activate the metal surface. Then, the round bottom flask was lowered away from the condenser, and the magnesium was added to it. After that, 10 ml of anhydrous diethyl ether was added in a round bottom flask by using the syringe, and the reaction flask was heated using a heating mantle to maximize the formation of the Grignard reagent. After 10 minutes of heating the mixture, the mixture changed color from clear to yellowish, and it turned completely Reddish brown after 12 minutes. After 28 minutes, the mixture stopped boiling, and approximately 4.5 ml of bromobenzene was added drop by drop in the mixture, and color of the mixture was turned light brown orange. Then, the phenylmagnesium bromide was cooled in ice bath for a few minutes, and 10 ml of anhydrous diethyl ether was added in the mixture by using the syringe. After that, approximately 2.3 ml of methyl benzoate was added to the reaction, and it was added slowly slowly because the reaction was exothermic which needed to be cool in order to maintain a gentle reflux. Once all the methyl benzoate solution was added, the heating mantle was removed from the reaction flask and was cooled to the room temperature. During the reaction, a milky white salt began to precipitate, and the reaction flask was swirled for ten minutes until most of the reaction became visibly subdivided. The contents of the reaction flask were slowly poured into the 250 ml Erlenmeyer flask which already contained 13.75 g ice and 25 ml of 10% H2SO2. The round bottom-flask was rinsed with 2.0 mL of 10% H2SO4 and 2.0 mL of diethyl ether, and the rinses were added to the mixture in an Erlenmeyer flask. Then, the mixture was swirled until all the salt was hydrolyzed, and the product distributed well into the ether layer. A

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