Question

Question: Devise a synthesis of each compound from benzene.

a.

b.

c.

d.

Short answer

Answer

a.

b.

c.

d.

Step-by-step solution

Substitution product of aryl diazonium salts

Aryl diazonium salts undergo substitution of N₂O by an atom or group of atoms to form substituted benzene derivatives.

Synthesis of the compound from benzene

Benzene undergoes nitration-reduction to form aniline which reacts with nitrous acid forming a diazonium salt.

a. Diazonium salt reacts with fluoroboric acid (HBF₄) to form an aryl fluoride.

Synthesis of aryl fluoride

b. Diazonium salt reacts with H₂O to form a benzene-1,3-diol (resorcinol).

Synthesis of benzene-1,3-diol

c. O-toluidine forms diazonium salt when it reacts with KI to give 2-iodotoluene.

Synthesis of 2-iodotoluene

d. The diazonium salt reacts with phosphoric acid (H₃PO₄) to give 1,3,5-trichloro benzene.

Synthesis of 1,3,5-trichloro benzene