Benzophenone Lab Report

Any amount of H2O present would react with and therefore ruin the Grignard reagent. The negative charge on the Grignard carbon would pop a proton off of water, and the resulting hydroxide would react with MgBr2. Since all of the water and moisture was removed, the reaction should run successfully. For this experiment’s reaction, bromobenzene is turned into phenylmagnesium bromide, a Grignard reagent. Then, the Grignard reagent is reacted with benzophenone to yield a molecule with a negative charge on the oxygen. This molecule is worked up and protonated to yield triphenylmethanol.

The objective of this experiment is to separate a 50:50 mixture of benzoic acid and benzil by using macroscale extraction. In the experiment, organic solvent diethyl ether is used. After adding 1.0 gram of the 50:50 mixture of benzoic acid and benzil to a 25ml Erlenmeyer flask, diethyl ether was added to the flask to dissolve the mixture. Benzoic acid and benzil dissolve in diethyl ether. Once the mixture dissolved in

The purpose of this experiment was to synthesize the Grignard reagent, phenyl magnesium bromide, and then use the manufactured Grignard reagent to synthesize the alcohol, triphenylmethanol, by reacting with benzophenone and protonation by H3O+. The triphenylmethanol was purified by recrystallization. The melting point, Infrared Spectroscopy, 13C NMR, and 1H NMR were used to characterize and confirm the recrystallized substance was triphenylmethanol.

17) Pour a small amount of the hot solvent into the flask containing the solid.

9-anthraldehyde and (carbethoxymethylene)triphenylphosphorane were reacted together using the Wittig reaction to produce E-3-(9-Anthryl)-2-propenoic acid ethyl ester. .100 g of 9-anthraldehyde and .180 g of (carbethoxymethylene)triphenylphosphorane were used. 9-anthraldehyde was a green powder while (carbethoxymethylene)triphenylphosphorane was a white powder. Both were added together into a 3.00 mL conical vial with a magnetic spin valve. The vial was inserted into a 120 C sand bath to melt the reagents. Once the reagents melted, they were stirred for 15 minutes (2:30 pm-2:45 pm). After stirring, the vial was removed to cool to room temperature. 3.00 mL of hexanes were added to the vial and the suspension was stirred. The solvent was removed

About 80 mL of HCl was obtained and mixed with phenolphthalein. Using a LabQuest unit and Gas Pressure Sensor kit, the HCl mixture was added to the flask with the magnesium ribbon and allowed to react. When reaction was complete, the change of temperature and gas was recorded. This procedure was repeated for different masses of magnesium ribbon (masses found on page 89 of the lab manual). After the completed procedure, moles of H₂ produced in each trial were calculated. (The actual procedure can be found on pages 87-89 of the lab manual)

When the heat was added to the flask the residue dissolved and the reactant mixture was clear.

Samples of benzophenone, malonic acid, and biphenyl were each tested with water, methyl alcohol, and hexane. Benzophenone was insoluble in water as it is nonpolar while water is highly polar. Benzophenone was soluble in methyl alcohol, dissolving in 15 seconds, because methyl alcohol is intermediately polar as benzophenone is nonpolar. Methyl alcohol is polar but not as much as water. Thus, the nonpolar benzophenone was soluble in methyl alcohol. Benzophenone was partially soluble in hexane because hexane is nonpolar as is benzophenone. Thus, benzophenone was dissolved in hexane. Malonic acid was soluble in water because both malonic acid and water are polar. It took 25 seconds for malonic acid to dissolve in water. Malonic acid was soluble in methyl alcohol because malonic acid is polar and methyl alcohol is intermediately polar, allowing malonic acid to dissolve in the methanol in 15 seconds. Malonic acid was insoluble in hexane because hexane is nonpolar while malonic acid is polar. Biphenyl was insoluble in water as water is highly polar whilst biphenyl is nonpolar. Biphenyl was partially soluble in methanol which is intermediately polar whilst biphenyl is nonpolar, allowing it to dissolve a little. Biphenyl was soluble in hexane because both biphenyl and hexane are nonpolar molecules. Biphenyl dissolved in hexane in 10 seconds.

The product obtained had a melting point of approximately 107 °C and a weight of .324 grams. Some of the product would not dissolve in water and so was removed through vacuum filtration, which left .141 g not dissolved in solution. It took 13.2 mL of sodium hydroxide to turn the solution of the product dissolved in water pink. A molecular weight of 138.63 g/mol was calculated from the data. These results indicate that the product was 2-methylbenzoic acid, the Grignard reagent was 2-methylphenylmagnesium bromide, and the unknown bromide solution was 2-methylbromobenzene. Calculations showed that the limiting reagent of the Grignard preparation was magnesium and that the experiment had a 23.13 % yield.

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

In a 25-mL round-bottom flask, 1-chlorobutane (5 mL, 4.32 g, 0.046 mol), sulfuryl chloride (1.6 mL, 2.7 g, 0.02 mol), 2,2’-azobis-(2-methylpropionitrile) (0.03 g), and a boiling chip were added. After a condenser and gas trap were attached to the flask, the mixture was heated to a gentle reflux in a steam bath for 20 min. The flask was then allowed to cool down quickly in an ice bath for a short time before a second portion of the 2,2’-azobis-(2-methylpropionitrile) (0.03 g) was added to the flask. The mixture was refluxed for another 10 min. before the flask was cooled in a beaker of water. The reaction mixture was then poured into a small separatory funnel already filled with water (10 mL),

The reaction took place in a conical vial and .2mL of each of the reactant samples were added to it along with some 95% ethanol. Two drops of NaOH were added shortly after and stirred at room temperature for fifteen minutes. The vial was cooled in and ice bath and crystallized. Vacuum filtration was performed to filter the crude product. The crude product was recrystallized using methanol and filtered again. We made one change to the procedure and instead of using .7mL of ethanol we

As the acid was being added, the mixture was being stirred over a stir plate. Once completed, the reaction mixture was poured from the round bottom flask into a 500 mL separatory funnel and its top (organic) layer was extracted into another beaker. The bottom (aqueous) layer was placed back into the funnel and extracted twice with 50.0 mL of ethyl ether each. The newly extracted layers were combined and dried over magnesium sulfate (MgSO4). The dried solution was the decanted into a beaker to remove the MgSO4 salts and the product solution was collected via Buchner vacuum filtration. The resulting product was transferred into an Erlenmeyer flask with an inverted beaker on top and stored in a drawer.

5.3 mL of bromobenzne and 15 mL of anhydrous ether was then placed into the separatory funnel and was shaken and vented in order to mix the solution. Half of the bromobenzene solution was added first into the round bottom flask and as soon as a color change was observed, the remaining half of the bromobenzene was added drop wise into the round bottom flask. The mixture was then refluxed on a heating mantle for 10 minutes until most of the magnesium has been consumed.

The beaker containing the HCl and antacid solution was placed on a hot plate to further dissolve and remove any gas. Once the solution was completely dissolved, 20mL of the HCl and antacid solution was pipetted out into each 150mL beaker. Three drops of phenolphthalein were added to each beaker. One beaker containing 20 mL of HCl and antacid with phenolphthalein was placed underneath the burette and carefully titrated with NaOH until the solution in the beaker was light pink. The amount of NaOH that was displaced in the burette was recorded.