Question

A Compound (A) with molecular formula C₂H₃N on acid hydrolysis gives (B) which reacts with thionyl chloride to give compound (C). Benzene reacts with compound (C) in presence of anhydrous AlCl₃ to give compound (D). Compound (D) on reduction with Zn/Hg and Conc. HCl gives (E). Identify (A), (B), (C), (D) and (E). Write the equations.

Answer 1

1. Compound (A) with molecular formula C₂H₃N is methyl cyanide. (CH₃CN)

2. Methyl cyanide (A) on hydrolysis gives acetic acid (B)

\[\ce{\underset{\underset{(A)}{(Methyl cyanide)}}{CH3CN} ->[H^+/H2O][excess] \underset{\underset{(B)}{(Acetic acid)}}{CH3COOH}}\]

3. Acetic acid (B) with thionyl chloride to give acetyl chloride (C)

\[\ce{\underset{\underset{(B)}{(Acetic acid)}}{CH3COOH} ->[SOCl2] \underset{\underset{(C)}{(Acetyl chloride)}}{CH3COCl} + SO2 + HCl}\]

4. Benzene reacts with acetyl chloride (C) in the presence of anhydrous AlCl₃ to give acetophenone (D)

5. Acetyl chloride (C) on reduced in the presence of Pd/H₂ and Barium sulphate, to gives acetaldehyde (E).

\[\ce{\underset{\underset{(C)}{(Acetyl chloride)}}{CH3COCl} ->[Pd/H2][BaSO4] \underset{\underset{(E)}{(Acetyldehyde)}}{CH3CHO} + HCl}\]

A	CH3CN	Methyl cyanide
B	CH3COOH	Acetic acid
C	CH3COCl	Acetyl chloride
D		Acetophenone
E	CH3CHO	Acetaldehyde