posted by Ankita on .
1. Below are the IR and 1H NMR spectra for a compound with the molecular formula of C11H16O. List all the possible information coming from each spectra, and then use this to elucidate the structure from the possible compounds shown. Briefly explain your rationale.
Molecular formula information (i.e., degrees of saturation):
Infrared Spectrum information:
2. Benzocaine (ethyl p-aminobenzoate) is a local anesthetic that can be prepared by direct esterification of p-aminobenzoic acid with ethanol. (remember that you carried out esterification in the experiment involving the synthesis of aspirin, although you used an anhydride to do so). Using a sulfuric acid as a catalyst (i.e.-acidic conditions), write the detailed mechanism for this reaction.
3. Refer back to the synthesis of aspirin to answer the following questions:
a.) If you used 5.0 g of salicyclic acid and excess acetic anhydride, what would be the theoretical yield of acetylsalicyclic acid in moles? In grams?
b.) A student performed the reaction in this experiment using a water bath at 90°C instead of 50°C. The final product was tested for the presence of phenols with ferric chloride. This test was negative, i.e., no change in color was observed. However, the melting point of the dry product was found to be 122-125°C. Explain these results as completely as possible.
4. Refer back to the Grignard reaction to answer the following questions:
a.) Benzene is often produced as a side-product during Grignard reactions using phenylmagnesium bromide. How can its formation be explained? Give a balanced equation and full mechanism for its formation.
b.) Provide methods for preparing the following compounds by the Grignard method. Identify the starting material for preparing the Grignard reagent, and the reactant it must react with in order to produce the target compound.
5. Refer back to the aldol condensation experiment to answer the following questions:
a.) Give a mechanism for product expected from the reaction of p-anisaldehyde with acetophenone.
b.) How might self-condensation of acetophenone ( which would lead to a nuisance by-product ) be minimized during the synthesis of the above product?
c.) What starting materials would you use to prepare the following compound?