Which of the following statements relating to aniline is not...

Which of the following statements relating to aniline is not true? (a) Aniline on Schotten-Baumann reaction gives benzanilide. (b) Aniline cannot be prepared by the reduction of benzonitrile with LiAlH $_{4}$. (c) On heating with conc. $\mathrm{H}_{2} \mathrm{SO}_{4}$ at $180^{\circ} \mathrm{C}$, aniline gives sulphanilic acid. (d) Aniline liberates nitrogen on treatment with ice cold nitrous acid.

Which of the following statements relating to aniline is not true?
(a) Aniline on Schotten-Baumann reaction gives benzanilide.
(b) Aniline cannot be prepared by the reduction of benzonitrile with LiAlH $_{4}$.
(c) On heating with conc. $\mathrm{H}_{2} \mathrm{SO}_{4}$ at $180^{\circ} \mathrm{C}$, aniline gives sulphanilic acid.
(d) Aniline liberates nitrogen on treatment with ice cold nitrous acid.

Key Concepts

Electrophilic Aromatic Substitution

This concept involves reactions where an electrophile replaces a hydrogen atom on an aromatic ring. Aniline is an example of an aromatic amine that is highly activated towards electrophilic substitution, which influences the outcome of subsequent reactions such as sulfonation and other substitution reactions. Understanding this reactivity helps explain why certain reaction conditions are needed to direct the substitution and control side reactions.

Schotten-Baumann Reaction

The Schotten-Baumann reaction is a method for acylating amines, where an amine reacts with an acyl chloride under biphasic conditions, typically leading to the formation of an amide. In the context of aniline, this reaction is used to synthesize compounds like benzamides, illustrating the utility of this method in modifying aromatic amines via nucleophilic acyl substitution.

Reduction of Nitriles

Reduction of nitriles is a key technique in synthetic organic chemistry where a nitrile group is transformed into an amine using reducing agents such as LiAlH4. This reaction illustrates the methods available for converting a carbon–nitrogen triple bond into a primary amine group, which is fundamental in the synthesis of aromatic amines like aniline. It also highlights the importance of selecting appropriate reducing agents for achieving the desired transformation.

Diazotization Reaction

Diazotization involves the conversion of primary aromatic amines into diazonium salts by treatment with nitrous acid, typically under cold conditions. The reaction is pivotal in organic synthesis because the resulting diazonium salts can form a variety of products through further transformations. One hallmark of this reaction is the liberation of nitrogen gas, which serves as an indication of the formation and decomposition of the diazonium intermediate.

Sulfonation of Aromatic Amines

Sulfonation is a type of electrophilic aromatic substitution where a sulfonic acid group is introduced onto an aromatic ring, often using concentrated sulfuric acid. With aromatic amines like aniline, the process is complicated by their high reactivity, which may lead to side reactions or rearrangements. Understanding the conditions under which sulfonation occurs helps explain how products like sulphanilic acid are formed, and why reaction conditions need to be carefully controlled.

Please give Ace some feedback