Preparation Of Triphenylmethanol By a Grignard Rea

Lab 2: Preparation of Triphenylmethanol by a Grignard Reaction

launching:

The Grignard addition of an organomagnesium compound to a carbonyl to form an alcoholic drink is one of the classic responses in organic chemistry. First, magnesium impart be inserted into a carbon-halide bond to form nucleophilic phenylmagnesium halide Grignard reagent. This reaction is an oxidation of the metal converting Mg0 to Mg2+ carried out in anhydrous vinyl ether solvent. This work will be done with care due to the moisture sensitivity of the phenylmagnesium halide. Second, methyl benzoate is added to form a new carbon-carbon sigma bond. The mediate magnesium alkoxide will wherefore be hydrolyzed to form 3rd alcohol product.

Experimental Procedure:

Part A: Preparing the Grignard reagent

I set 1.98 grams of magnesium turnings into a cleaned 250mL round-bottom flask and then attached the calcium chloride drying tube into the round-bottom flask
Then, I placed this flask onto a heating chimneypiece and adjust the command to setting 6. This flask is heated until it was too warm to touch.
After the flask was heated, I removed it from the heating mantel and allowed it to cool to room temperature.




Next, I poured 15mL of exacting ether and 9mL of bromobenzene into the 250mL flask and waited 5 minutes for any reaction.
There were no signs of reaction after 5 minutes; therefore the lab auxiliary used a glass stirring rod to bray the magnesium in high society to get the reaction started. When this was done, the runniness became cloudy, rapidly bubbling, and the color turned rusty red.
Next, I added 25mL of absolute ether and attached a reflux condenser to the flask. I turned on the water when I saw ether vapor had successfully wet the joint at the head of the condenser.
Every 60 seconds, I swirled the flask and I proceed to perform this action until I saw that the reaction halt bubbling.
When I noticed that the liquid level decreased beneath the marked level, I...If you want to get a full essay, order it on our website: Orderessay



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