Chemistry - Carbonyl compounds Question with Solution | TestHub
Compound gives yellow coloured precipitate with 2,4-DNP but does not give red colored precipitate with Fehling's solution. (X) on treatment with gives compound when treated with dil. gives isomeric compound (Z). (Z) on hydrolysis gives propanoic acid and aniline. What will be the structure of (X), (Y) and (Z)?
Options:
Answer:
Solution:
(1)Information about X:
Molecular formula: C₉H₁₀O
Gives yellow ppt with 2,4-DNP → carbonyl compound ✔
Does NOT give Fehling’s test → not an aldehyde ⇒ ketone
Aromatic ketone with formula C₉H₁₀O → Propiophenone
(2) Reaction of X with NH₂OH / H⁺
Carbonyl + hydroxylamine → Oxime formation
Product Y is oxime
Formula matches C₉H₁₁NO
Reaction type: Oxime formation (nucleophilic addition)
(3) Reaction of Y with dil. H₂SO₄
Oxime on acidic treatment undergoes Beckmann rearrangement
Gives amide (Z)
For ketoxime:
Aryl group migrates preferentially
Product: Propanilide type amide
(4) Hydrolysis of Z
Amide hydrolysis → carboxylic acid + amine
Given: Propanoic acid + Aniline (confirms structure)