An aromatic compound ‘A’ on heating with Br₂ and KOH forms a compound ‘B’ of molecular formula C₆H₇N which on reacting with CHCl₃ and alcoholic KOH produces a foul smelling compound ‘C’. Write the structures and IUPAC names of compounds A, B and C.

Question

An aromatic compound ‘A’ on heating with Br₂ and KOH forms a compound ‘B’ of molecular formula C₆H₇N which on reacting with CHCl₃ and alcoholic KOH produces a foul smelling compound ‘C’. Write the structures and IUPAC names of compounds A, B and C.

Philoid · Accepted Answer

•The reagents Br₂ with KOH (strong base) is used in the Hoffman reaction. This reaction is used to convert amides to amines with the loss of carbonyl carbon atom.

•The given molecular formula of ‘B’ is C₆H₇N, and as per Hoffman reaction, this should be an amine.

•Also, it is mentioned that the starting product, ‘A’ is aromatic, therefore ‘A’ is an aromatic amide which loses carbonyl carbon atom upon reaction with Br₂ and KOH.

•Hence, for the molecular formula of ‘A’, we should add -CO to the molecular formula of ‘B’.

C₇H₇NO is the molecular formula of aromatic amide ‘A’.

The only aromatic amide having this molecular formula is benzamide.

Structure of ‘A’

Hoffman Reaction occurs and ‘B’ is formed.

•Aniline reacts with CHCl₃ and KOH, by carbylamine reaction to give a foul smelling compound ‘C’, benzene isonitrile.

An aromatic compound ‘A’ on heating with Br2 and KOH forms a compound ‘B’ of molecular formula C6H7N which on reacting with CHCl3 and alcoholic KOH produces a foul smelling compound ‘C’. Write the structures and IUPAC names of compounds A, B and C.

An aromatic compound ‘A’ on heating with Br₂ and KOH forms a compound ‘B’ of molecular formula C₆H₇N which on reacting with CHCl₃ and alcoholic KOH produces a foul smelling compound ‘C’. Write the structures and IUPAC names of compounds A, B and C.