Question

The compound that does not undergo Friedel-Crafts alkylation reaction but gives a positive carbylamine test is :

• A. Aniline
• B. Pyridine
• C. N-methylaniline
• D. Triethylamine

Answer 1

The Correct Option is A

Friedel-Crafts alkylation requires an electrophilic aromatic substrate. Aniline does not undergo Friedel-Crafts alkylation because the amino group (-\(NH_2\)) on the benzene ring strongly activates the ring towards electrophilic attack, leading to significant reactivity and making it difficult to control the reaction. Furthermore, the lone pair of electrons on the nitrogen atom in aniline coordinates with the Lewis acid catalyst (like \(AlCl_3\)),
deactivating the ring and preventing alkylation.
The carbylamine test is positive for primary amines. Aniline is a primary amine and will give a positive test.