The amine ‘A’ when treated with nitrous acid gives yellow oily substance. The amine A is

Question

The amine ‘A’ when treated with nitrous acid gives yellow oily substance. The amine A is (A) triethylamine (B) trimethylamine (C) aniline (D) methylphenylamine

Tardigrade Admin · Accepted Answer

Secondary amines when treated with nitrous acid give yellow oily substance. So, amine '

A^{'}

is methylphenyl amine.

Reaction of nitrous acid with allphatic amines

Liberation of

N_{2}

gas

+

alcohol formation

R - N H_{2} + H N O_{2} ⟶ R - N + \equiv NC l^{-}

⟶ H_{2} O RO H + N_{2} + H Cl

Reaction of nitrous acid with aromatic amines

Liberation of

N_{2}

gas

+

Phenol formation

P h N H_{2} + H N O_{2} + H Cl ⟶ 273 - 278 K

P h - N + \equiv NC l^{-} ⟶ P h O H + H Cl + N_{2}

Reaction of nitrous acid with

2^{\circ}

amines With

H N O_{2}

, they give nitroso amines, which being insoluble in dilute acids separate as yellow oily compound.

R_{2} N H + H ONO ⟶ R_{2} - N - N = O

N-nitroso dialkyl amine (yellow oil)

Reaction of nitrous acid with

3^{\circ}

amines

Aliphatic

3^{\circ}

amines on reaction with HONO form soluble nitrite salts, while aromatic

3^{\circ}

amines form green coloured

p

-nitroso amines.

R_{3} N + H ONO ⟶ (Soluble nitrite) [R_{3} N + H] N O_{2}^{-}

P h - NM e_{2} + H ONO ⟶

Q. The amine ‘A’ when treated with nitrous acid gives yellow oily substance. The amine A is

triethylamine

trimethylamine

aniline

methylphenylamine

Q. The amine ‘ $A$ ’ when treated with nitrous acid gives yellow oily substance. The amine $A$ is