Question

Q.27)
Which of the following method cannot be
used for preparation of aromatic amine ( 1
marks)
Ans.
Decarboxylation of amino acids
Gabriel phthalimide synthesis
Reduction of nitro compound
Reduction of nitrile with LiAI4​

Answer 1

Answer:

Decarboxylation of amino acids

Gabriel phthalimide synthesis

Reduction of nitro compound

Reduction of nitrile with LiAI4

Answer 2

OPTION (2) IS CORRECT.

(2) GABRIEL PHTHALIMIDE SYNTHESIS.

Explanation:

• In Gabriel phthalimide synthesis a phthalimide is treated with KOH in presence of alkyl halide, to form N-alkylphthalimide. Then it is treated with sodium hydroxide to obtain an aliphatic amine.
• The alkyl group used in alkyl halide, forms the amine as aryl halides do not undergo nucleophilic substitution with the anion formed by phthalimide.
• The decarboxylation of amino acids, reduction of nitro compound, and reduction of nitrile with lithium aluminum hydride gives aromatic amine, as these can undergo substitution.
• Therefore, option (2) is correct, it cannot be used to prepare aromatic amine.