Question

Show how each of the following compounds can be synthesized from benzene:

a. o-bromopropylbenzene

b. m-nitrobenzoic acid

c. p-nitrobenzoic acid

d. p-chloroaniline

e. m-chloroaniline

f. m-xylene

g. 2-phenylpropene

h. m-bromopropylbenzene

i. 1-phenyl-2-propanol

Short answer

a)

b)

c)

d)

e)

f)

g)

h)

i)

Step-by-step solution

Step-by-step-solutionStep 1: Friedel crafts reactions

Friedel–Crafts reactions are the slowest of the electrophilic aromatic substitution reactions. Therefore, if a benzene ring has been moderately or strongly deactivated that is if it has a meta-directing substituent—it will be too unreactive to undergo either Friedel–Crafts acylation or Friedel–Crafts alkylation.

Formation of the products

a)

Benzene undergoes Friedel crafts alkylation followed by bromination to form ortho and para products. The reaction is represented as follows:

Formation of the desired product (a)

b)

Benzene undergoes Friedel crafts alkylation followed by oxidation with ${\mathrm{KMnO}}_4$, then nitration followed by reaction with NaOH, HCl, and water to form m-nitrobenzoic acid.

Formation of the desired product (b)

c)

Benzene undergoes Friedel crafts alkylation followed by nitration and then oxidation withlocalid="1652445847795" ${\mathrm{KMnO}}_4$to form p-nitro benzoic acid. The reaction is represented as follows:

Formation of the desired product (c)

d)

Benzene undergoes chlorination in the presence of localid="1652445923979" ${\mathrm{Cl}}_2$and localid="1652445931186" ${\mathrm{FeCl}}_3$, followed by nitration and then reduction with Sn/HCl to form p-chloro aniline. The reaction is represented as follows:

Formation of the desired product (d)

e)

Benzene undergoes nitration, followed by chlorination in the presence of localid="1652445938673" ${\mathrm{Cl}}_2$and localid="1652445947686" ${\mathrm{AlCl}}_3$,then undergoes a reduction in the presence of Zn/Hg in the presence of HCl to form m-chloro aniline. The reaction is represented as follows:

Formation of the desired product (e)

f)

Benzene undergoes Friedel crafts acylation to form 2 substituted products, followed by reaction with localid="1652445960173" ${\mathrm{I}}_2$and NaOH, then reaction withlocalid="1652445967662" ${\mathrm{H}}_2\mathrm{O}/{\mathrm{H}}^{+}$and undergoes reduction with red P and HCl to form m-xylene. The reaction is represented as follows:

Formation of the desired product (f)

g)

Benzene undergoes Friedel crafts alkylation followed by bromination, and finally undergoes hydrolysis in the presence of localid="1652445749797" ${\mathrm{OH}}^{-}$to form 2-phenyl propene. The reaction is represented as follows:

Formation of the desired product (g)

h)

Benzene undergoes Friedel crafts acylation in the presence of ${\mathrm{AlCl}}_3$followed by bromination, and then reduction in the presence of Pd/C to form m-Bromo propyl benzene. The reaction is represented as follows:

Formation of the desired product (h)

i)

Benzene undergoes Friedel crafts alkylation followed by bromination, and undergoes hydrolysis in the presence of ${\mathrm{OH}}^{-}$to form 2-phenyl propene which reacts with${\mathrm{BH}}_3/\mathrm{THF}$,then undergoes hydrolysis to form 1-phenyl-2-propanol. The reaction is represented as follows:

Formation of the desired product (i)