Question

Which of the following organic compound(s) do not undergo carbylamine reaction?

• A. $(C_2{H}_5{)}_{2}NH$
• B. $C_2{H}_{5}N{H}_2$
• C. $(C_2{H}_5{)}_{3}N$
• D. $(C_2{H}_5{)}_4{N}^{+}{I}^{-}$
  

Answer 1

Answer: (A), (C), (D)

$(C_2{H}_5{)}_4{N}^{+}{I}^{-}$


Carbylamine reaction mechanism includes the addition of amine to the intermediate created from the dehydrohalogenation of chloroform. This intermediate is called dichlorocarbene. The carbylamine reaction is also known as Hoffmann isocyanide synthesis. It is the reaction of a primary amine, chloroform and a base to synthesize isocyanides. The dichlorocarbene intermediate is very important for this conversion. The carbylamine reaction cannot be used to synthesize isocyanides from secondary or tertiary amines.

Carbylamine reaction is given by only primary amine. Hence $C_2{H}_{5}N{H}_2$ gives carbylamine reaction as it is the only primary amine out of the given options.
$R-N{H}_2+CHC{l}_3+3KOH\left(alcoholic\right)\stackrel{\Delta }{\to }R-NC+3KCl+3H_{2}O$
Hence, (a),(c) and (d) do not give carbylamine reaction and are the correct options.