Question

The following two reactions give the same foul smelling product \(Z\):

\[ {C2H5CONH2 →[Br2/NaOH] X} \] \[ {X →[CHCl3/alcoholic\ KOH][\Delta] Z} \] \(X\) and \(Z\), respectively, are:

• A. \(X={C2H5CN},\ Z={C2H5NC}\)
• B. \(X={C2H5NH2},\ Z={C2H5CN}\)
• C. \(X={C2H5NH2},\ Z={C2H5NC}\)
• D. \(X={CH3NH2},\ Z={CH3NC}\)

Hint:

Hofmann bromamide reaction converts amide into amine with one carbon less, and carbylamine reaction converts primary amine into foul-smelling isocyanide.

Answer 1

The Correct Option is C

The given reactions involve the conversion of compounds to produce a foul-smelling product \(Z\). Let's analyze each step to identify the intermediates and final product.

1. First Reaction: \({C2H5CONH2 →[Br2/NaOH] X}\)
   • This reaction is known as the Hoffmann Bromamide Degradation Reaction.
   • In this reaction, acetamide \((C_2H_5CONH_2)\) is treated with bromine and sodium hydroxide, resulting in an amine with one fewer carbon atom.
   • Thus, the product \(X\) is ethylamine \(C_2H_5NH_2\).
2. Second Reaction: \({X →[CHCl3/alcoholic\ KOH][\Delta] Z}\)
   • This reaction is the Carbylamine Reaction, which is used to synthesize isocyanides (also known as carbylamines), which have a characteristic foul smell.
   • When ethylamine \((C_2H_5NH_2)\) is treated with chloroform \((CHCl_3)\) and alcoholic potassium hydroxide \((KOH)\) under heating \((\Delta)\), it forms ethyl isocyanide \((C_2H_5NC)\).
   • Hence, the product \(Z\) is ethyl isocyanide \(C_2H_5NC\).

These steps lead us to identify that:

• \(X = C_2H_5NH_2\)
• \(Z = C_2H_5NC\)

Correct answer: \(X={C2H5NH2},\ Z={C2H5NC}\)