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Reaction Sequence Involving Phthalimide and Gabriel Phthalimide Synthesis

For the reaction sequence given below, the correct statement(s) is(are)

Question Diagram 1

Options

A

Both X\mathbf{X} and Y\mathbf{Y} are oxygen containing compounds.

Correct
B

Y\mathbf{Y} on heating with CHCl3/KOH\text{CHCl}_3/\text{KOH} forms isocyanide.

C

Z\mathbf{Z} reacts with Hinsberg's reagent.

Correct
D

Z\mathbf{Z} is an aromatic primary amine.

Step-by-Step Solution

To determine the correct statements, let us analyze the reaction sequence step by step:

  1. Formation of Compound X\mathbf{X}:

    • Step (i): Tetralin (1,2,3,41,2,3,4-tetrahydronaphthalene) is subjected to strong oxidation with acidic potassium permanganate (KMnO4/H+,Δ\text{KMnO}_4/\text{H}^+, \Delta). The saturated alicyclic ring undergoes cleavage to yield phthalic acid (benzene-1,21,2-dicarboxylic acid): TetralinKMnO4,H+,ΔPhthalic acid (C8H6O4)\text{Tetralin} \xrightarrow{\text{KMnO}_4, \text{H}^+, \Delta} \text{Phthalic acid } (\text{C}_8\text{H}_6\text{O}_4)
    • Step (ii): Reaction of phthalic acid with ammonia (NH3\text{NH}_3) followed by heating leads to the elimination of two water molecules (2H2O-2\text{H}_2\text{O}) to form phthalimide (X\mathbf{X}): Phthalic acid+NH3Δ,2H2OPhthalimide (X,C8H5NO2)\text{Phthalic acid} + \text{NH}_3 \xrightarrow{\Delta, -2\text{H}_2\text{O}} \text{Phthalimide } (\mathbf{X}, \text{C}_8\text{H}_5\text{NO}_2)
    • Compound X\mathbf{X} is phthalimide, which is an oxygen-containing compound (contains two carbonyl oxygens).
  2. Formation of Compound Y\mathbf{Y}:

    • Phthalimide (X\mathbf{X}) is treated with ethanolic KOH\text{KOH} to form potassium phthalimide, which then undergoes a nucleophilic substitution reaction (SN2S_N2) with alkyl bromide (R-Br\text{R-Br}). This is the classic Gabriel phthalimide synthesis: Phthalimide (X)(ii) Ethanolic KOH, (iii) R-Br(i) Strong heatingN-alkylphthalimide (Y)\text{Phthalimide } (\mathbf{X}) \xrightarrow[\text{(ii) Ethanolic KOH, (iii) R-Br}]{\text{(i) Strong heating}} N\text{-alkylphthalimide } (\mathbf{Y})
    • Compound Y\mathbf{Y} is NN-alkylphthalimide (C8H4O2N-R\text{C}_8\text{H}_4\text{O}_2\text{N-R}), which also contains oxygen atoms.
  3. Formation of Compound Z\mathbf{Z}:

    • Alkaline hydrolysis of NN-alkylphthalimide (Y\mathbf{Y}) using aqueous NaOH\text{NaOH} yields sodium phthalate (aromatic compound) and a primary aliphatic amine (Z\mathbf{Z}): N-alkylphthalimide (Y)NaOHDisodium phthalate (Aromatic compound)+R-NH2(Z)N\text{-alkylphthalimide } (\mathbf{Y}) \xrightarrow{\text{NaOH}} \text{Disodium phthalate (Aromatic compound)} + \text{R-NH}_2 (\mathbf{Z})
    • Compound Z\mathbf{Z} is an aliphatic primary amine (R-NH2\text{R-NH}_2).

Evaluation of Options:

  • (A) Both X\mathbf{X} and Y\mathbf{Y} are oxygen containing compounds:

    • X\mathbf{X} (phthalimide) contains two carbonyl oxygen atoms (C8H5NO2\text{C}_8\text{H}_5\text{NO}_2).
    • Y\mathbf{Y} (NN-alkylphthalimide) also contains two carbonyl oxygen atoms (C8H4O2N-R\text{C}_8\text{H}_4\text{O}_2\text{N-R}).
    • Statement (A) is CORRECT.
  • (B) Y\mathbf{Y} on heating with CHCl3/KOH\text{CHCl}_3/\text{KOH} forms isocyanide:

    • The carbylamine test (CHCl3/KOH\text{CHCl}_3/\text{KOH}) is given exclusively by primary amines (1\text{1}^\circ amines).
    • Since Y\mathbf{Y} is an imide (NN-alkylphthalimide) and not a primary amine, it does not give the carbylamine test.
    • Statement (B) is INCORRECT.
  • (C) Z\mathbf{Z} reacts with Hinsberg's reagent:

    • Z\mathbf{Z} is a primary aliphatic amine (R-NH2\text{R-NH}_2). Primary amines readily react with Hinsberg's reagent (benzenesulfonyl chloride, C6H5SO2Cl\text{C}_6\text{H}_5\text{SO}_2\text{Cl}) to form NN-alkylbenzenesulfonamides.
    • Statement (C) is CORRECT.
  • (D) Z\mathbf{Z} is an aromatic primary amine:

    • Gabriel phthalimide synthesis yields an aliphatic primary amine (Z=R-NH2\mathbf{Z} = \text{R-NH}_2), not an aromatic primary amine (since aryl halides do not undergo SN2S_N2 substitution with potassium phthalimide).
    • Statement (D) is INCORRECT.

Conclusion:

The correct statements are A and C.

Reaction Sequence Involving Phthalimide and Gabriel Phthalimide Synthesis | Chemistry PYQ Solution - JEE Challenger