Compounds Containing Nitrogen

The Gabriel phthalimide synthesis is a method used to prepare primary aliphatic and aromatic amines. The process begins with phthalimide being treated with ethanolic potassium hydroxide (KOH), forming the potassium salt of phthalimide. This salt is then heated with an alkyl halide (RX), and subsequent treatment with either alkaline hydrolysis or hydrazinolysis (using hydrazine, $ \mathrm{H}_2\mathrm{N} \cdot \mathrm{NH}_2 $) yields the corresponding primary amine. However, this method cannot be used to synthesize primary aromatic amines that have electron-withdrawing groups (EWGs) at the ortho- and para-positions, such as the nitro group ($ -\mathrm{NO}_2 $). This limitation arises because aryl halides (ArX) do not undergo nucleophilic substitution ($\mathrm{S}_{\mathrm{N}}$) reactions with the anion formed by phthalimide.

$ \text { In the given reaction, the final product is as follows : } $

In step (i), we get diazonium product, which go for coupling reaction to give the final product as shown in the reaction. Hence, option (d) is the correct answer.

$ \text { The major product in the following reaction is } $

(i) $\mathrm{Sn} / \mathrm{HCl}$ show reduction.

(ii) $\mathrm{Br}_2$ show addition

(iii) Show formation of diazonium salt.

(iv) Show, the final product.

Hence, option (c) is the correct answer.

Step I Amide react with bromine and aqueous KOH to form amine.

Step II Amine react with $\mathrm{NaNO}_2, \mathrm{HCl}$ followed by hydrolysis form alcohol.

The correct answer is Option B: C₆H₅SO₂Cl.

Hinsberg's reagent is benzenesulfonyl chloride (C₆H₅SO₂Cl). It is used to differentiate primary, secondary, and tertiary amines.

Here's why the other options are incorrect :

• Option A: C₆H₅COCl is benzoyl chloride, a reagent used in Friedel-Crafts acylation reactions.


• Option C: SOCl₂ is thionyl chloride, a reagent used to convert alcohols into alkyl chlorides.


• Option D: (COCl)₂ is oxalyl chloride, a reagent used for the conversion of carboxylic acids into acid chlorides.

All the given compounds are acid derivatives, thus contain carbonyl group in them. LiAlH₄ reduces these compounds through nucleophilic substitution via addition elimination (S_NAE) reaction. The rate of reaction depends upon the following factors:

(i) Size of alkyl group.

(ii) Steric hinderance around the > C == O group.

(iii) (+) ve charge on the C-atom of > C == O group.

The alkyl groups are more or less same in the given compounds. Thus, the reactivity order of given compounds depends upon 2nd and 3rd factor written above. The cumulative effect of these two factors results to leaving group ability (LGA) of the substituents in the following order :

This leaving group ability (weak conjugate base) corresponds directly to the reactivity order.

Hence, the correct reactivity order is:

The complete pathway of reactions is as follows :

Then P, Q and R will be

Given

Now from S to major products its given.