Question

Which of the following amines will not undergo carblyamine reaction?

• A. N-methylthanamine
• B. Phenylmethanamine
• C. Aniline
• D. Ethanamine
• E. Propan-2-amine

Hint:

In carbylamine reaction, only primary amines react with carbon disulfide and alkali to give an isocyanide. Secondary amines and other non-primary amines do not participate in this reaction.

Answer 1

The Correct Option is A

Carbylamine reaction involves the reaction of a primary amine with carbon disulfide (CS₂) followed by the addition of an alkali to form an isocyanide or isothiocyanate. It is specific to primary amines.
Let's go through the options:
- (A) N-methylthanamine is a secondary amine, and secondary amines do not undergo carbylamine reaction because they do not have a free hydrogen atom attached to the nitrogen. Hence, N-methylthanamine will not undergo the carbylamine reaction.
- (B) Phenylmethanamine (also known as aniline) is a primary amine, and it will undergo the carbylamine reaction, forming an isocyanide.
- (C) Aniline is a primary amine (similar to phenylmethanamine) and will undergo the carbylamine reaction.
- (D) Ethanamine is a primary amine, so it will also undergo the carbylamine reaction.
- (E) Propan-2-amine is a secondary amine, and like N-methylthanamine, it will not undergo the carbylamine reaction because it is a secondary amine.
Therefore, the correct answer is N-methylthanamine.