Chem 2546 Spring 2025
Lab 1: Electrophilic Aromatic Substitution
Post-lab (65 pts total)
1
A: Upload a copy of your notebook page(s) from lab 1. (5 pts)
B: Answer the following questions (60 pts).
1. The following questions refer to the nitration of methyl benzoate.
a. What type of functional group is present in methyl benzoate? (2 pts)
b. Is the functional group in methyl benzoate electron donating or electron
withdrawing? What type of directing group is it? (2 pts)
c. Draw the mechanism showing the formation of the nitronium ion. (8 pts)
d. Draw the mechanism for the nitration of methyl benzoate, starting with the
nitronium ion and methyl benzoate. (10 pts)
e. In addition to mononitration products, the dinitro compound is a minor product of
this reaction. What techniques can be used to reduce or avoid the production of the
dinitro compound? (3 pts)
2. The following questions refer to the characterization of your reaction product.
a. Draw the 3 possible products from the mono-nitration of methyl benzoate and label
them as ortho, meta, and para. (6 pts)
b. The nitro group is the more polar functional group in the molecules above. With
this knowledge in hand, add net dipole arrows (with the correct relative magnitude)
to the structures above. (6 pts)
c. Circle the most polar molecule in 2(a). (2 pts)
d. Draw (or insert a picture) the TLC plate with the best separation from your
characterization and calculate the Rf values of your product and the 3 standards. (10
pts)
e. Based on the net dipole moments you drew in part b, do the locations of the standard
spots on the TLC plate make sense? Use what you know about TLC interactions to
justify your answer. (5 pts)
3. Calculate the percent yield for your reaction. Assume methyl benzoate is the limiting
reagent. Show all steps in your calculations. (6 Pts)
