Then, transfer 1 mL concentrated sulfuric acid into the tube labeled sulfuric acid. Nitrations are energetic reactions under harsh conditions. Allow the ice to melt. The actual yield methyl — 3- nitrobenzoate crude product is 2. After all the nitrating solution has been added, allow the mixture to stand in the ice-water bath for minutes.
Nitration of methyl benzoate formal lab report
All of the chemical material should be discarded properly in the container provided. In this experiment we will put a nitro NO2 group on a benzene ring, which already has an ester group, attached to it methyl benzoate. Heat the flask in a steam bath until the crystals are in solution and the solution boils. Since the NO2 group t is meta-director. Transfer 1 mL concentrated nitric acid into the tube labeled nitric acid. You will use this worksheet to record your answers to the In-Lab questions. Then, use a Pasteur pipet to very slowly add the cold sulfuric acid drop by drop into the cold nitric acid. Reaction scheme: The electronic nature of the substituent also directs the position of electrophilic substitution. There are three different regioisomers for disubstituted aromatic rings: orth, meta, and para.
After the mixed acids have been added, swirl the Test Tube in the ice bath for another minutes. Part 3 Place approximately 1 mL methyl benzoate into a mL Erlenmeyer flask and add 2.
Nitration of methyl benzoate major product
Waste Disposal The aqueous and ethanol washings from above are combined in a mL beaker. Add ice-cold ethanol to the flask and swirl to loosen the crystals. Since the NO2 group t is meta-director. Transfer 1 mL concentrated nitric acid into the tube labeled nitric acid. The percent yield of the recrystallized product was Conclusion: The electrophilic aromatic substitution reaction between methyl benzoate and a nitrating solution of sulfuric and nitric acids was successful and yielded methyl m-nitrobenzoate. Clamp the flask containing the mixture to a support stand. The pH is adjusted to lie between 5.
Then remove the flask from the sand bath and allow it to cool to room temperature. Using a Pasteur Pipet, add the cold mixture of acids drop by drop to the cold solution of the ester in sulfuric acid. The pH is adjusted to lie between 5.
There are three different regioisomers for disubstituted aromatic rings: orth, meta, and para.
Methyl benzoate 0. The meta-product forms because the ortho- and para- products both have very unstable resonance forms with 2 positive charges next to each other. The pH is adjusted to lie between 5. After adding all the sulfuric acid to the nitric acid, allow the nitrating solution to stand in the ice-water bath for 10 minutes. In the process the methyl benzoate was nitrated to form a methyl m-nitro benzoate. Use extreme caution in recrystallizing with this or any other flammable solvent. The observed melting point was close to the literature value of 78 - 80C for the meta-substituted product. Place the flask into the ice-water bath. After all the nitrating solution has been added, allow the mixture to stand in the ice-water bath for minutes. The ester group is the meta deactivator and the reaction takes place at the meta position because the ortho and para positions are destabilized by adjacent positives charges on the resonance structure. The percentage yield that we get is This should take min. Then filter the crystals using vacuum filtration. This was then compared with a data table given in the experiment in order to determine the regiochemistry of the obtained product.
The meta- position is electron-rich, and thus reacts best with the NO2 group to form methyl m-nitrobenzoate. Then, allow your product to air dry in the filter funnel for 10 minutes.
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