Question

The number of compounds from the following which can undergo reaction with \(Br_2/KOH\) (alcoholic) to give respective products and these products can also be obtained separately by Gabriel phthalimide reaction is :}

• A. 5
• B. 4
• C. 3
• D. 6

Answer 1

The Correct Option is C

Concept:
 

• \(Br_2/KOH\) causes Hofmann bromamide degradation.
• It converts an amide to a primary amine with one carbon less.
• Gabriel phthalimide synthesis gives only primary amines.

Thus, the required conditions are:

• The compound must be an amide
• The product must be a primary amine

Step 1: Check the given structures.
Compounds containing the group: \[ -CONH_2 \] undergo Hofmann rearrangement and produce primary amines.

Step 2: Exclude substituted amides.
Compounds with: \[ -CONHCH_3 \quad \text{or} \quad -CONHC_2H_5 \] produce secondary amines, which cannot be prepared by Gabriel synthesis.

Step 3: Count valid compounds.
Only those compounds which:

• Have \(-CONH_2\)
• Form primary amines

Number of such compounds: \[ 3 \] 
Final Answer:
\[ \boxed{3} \]