Question

The compound obtained by heating a mixture of a primary
amine and chloroform with ethanolic potassium hydroxide
(KOH) is
(a) an alkyl cyanide
(b) a nitro compound
(c) an alkyl isocyanide
(d) an amide

Answer 1

$\huge\mathcal\purple{Answer:-}$

(c) an alkyl isocyanide

Answer 2

The compound obtained by heating a mixture of a primary amine and chloroform with ethanolic potassium hydroxide (KOH) is (c) an alkyl isocyanide.

• The reaction of a primary amine with chloroform in the presence of ethanolic potassium hydroxide is called a carbylamine reaction or Hoffman's isocyanide test.

• This reaction produces a corresponding isocyanide as the major product.

• It is used as a test for primary amines.

• A foul smell given by this reaction confirms the presence of -NH₂ group in a compound.

• The reaction also gives potassium chloride and water molecules as by-products.

• The reaction can be generally represented as follows :

RNH₂ + CHCl₃ + 3 (alc.) KOH → RNC + 3KCl + 3H₂O

For example :

CH₃CH₂NH₂ (ethanamine) + CHCl₃ + 3 (alc.) KOH → CH₃CH₂NC (ethyl isocyanide) + 3KCl + 3H₂O