Consider the compounds below and answer the following questions. (a) Which compo
ID: 518417 • Letter: C
Question
Consider the compounds below and answer the following questions. (a) Which compound undergoes electrophilic aromatic substitution with mine without a Lewis acid catalyst? (b) Which compound from a carboxylic acid on treatment with KMnO_4? (c) Which compound can be made by Friedel-crafts alkylation, but not by Friedel-crafts acylation and reduction? (d) Which compounds can be fairly readily transformed into fluorobenzene (no more than 3 steps)? (e) Which compounds activate the molecule by resonance effect, but deactivate by inductive effect? (f) Which will form a meta product on reaction with HNO_3/H_2SO_4? (g) Which compound will form the para product (with little, if any, ortho product) on reaction with FeCl_3/Cl_2? (h) Which compounds cannot undergo Friedel-Crafts acylation?Explanation / Answer
a. Anisole (compound B) is haviing methoxy activating group. Therefore bromination goes without catallyst.
b. Toluene (compound A) on reaction with KMnO4 will give benzoic acid.
c. Compound A can be made from benzene using Fridel craft alkylation but not Fridel craft acylation.
d. Compound D and compound E can be converted into fluorobenzene.
Compound D on treatment with NaNO2 + HCl will give diazo compound which on treatment with HBF4 will give fluoro benzene.
e.Compound B and compound D activate the benzene ring by resonance. and deactivates by inductive effect (oxygen and nitrogen are more electronegative).
f. Compoound E on nitration will give meta product because it is a elecctron withdrawing group.
g. Compound A and compound C will give para product with FeCl3 and Cl2 because methyl and isobutyl and weakly activating groups.
H. Compound D and Compound E will not undergo Fridel craft acylation because nitro benzene elelctron density is less. Aniline nitrogen coordinates with FeCl3.