StemCET Logo

Chemistry Question 68 – JEE-MAIN 2026

← Back
The number of compounds from the following which can undergo reaction with Br2/KOH (alcoholic) to give respective products and these respective products can also be obtained separately by Gabriel phthalimide reaction is : 1. H5C6−CONH22. H5C6−CH2−CONH23. H3C−CONH24. H11C6−CONHCH2CH35. (H3C)3C−CONHCH36. H11C6−CONH2

Understand the requirements for Hofmann Bromamide Degradation and Gabriel Phthalimide Synthesis.

Step 1: Identify Reaction Requirements✦ Active

The question asks for compounds that satisfy two conditions: 1) undergo Hofmann Bromamide Degradation (HBD) with Br2/KOH (alcoholic), and 2) the amine product formed from HBD can also be synthesized by Gabriel Phthalimide Synthesis (GPS). HBD requires a primary amide (R−CONH2) and yields a primary amine (R−NH2). GPS synthesizes primary amines (R−NH2) and works best with primary alkyl halides (R−X), but not with secondary, tertiary, or aryl halides.

Step 2: Evaluate Compounds for Hofmann Bromamide Degradation○ Expand

Only primary amides (R−CONH2) undergo HBD. Let's check the given compounds: 1. H5C6−CONH2 (Primary amide) - Yes 2. H5C6−CH2−CONH2 (Primary amide) - Yes 3. H3C−CONH2 (Primary amide) - Yes 4. H11C6−CONHCH2CH3 (Secondary amide) - No 5. (H3C)3C−CONHCH3 (Secondary amide) - No 6. H11C6−CONH2 (Primary amide) - Yes So, compounds 1, 2, 3, and 6 are potential candidates.

💡 Teacher's Secret Hint

Remember that Hofmann Bromamide Degradation is specific to primary amides.

Step 3: Evaluate HBD Products for Gabriel Phthalimide Synthesis○ Expand

Now, we check if the primary amine product from HBD can be formed via GPS: 1. From H5C6−CONH2: Product is Aniline (H5C6−NH2). Aniline is an aryl amine and cannot be prepared by GPS. (Fails) 2. From H5C6−CH2−CONH2: Product is Benzylamine (H5C6−CH2−NH2). Benzylamine is a primary amine and can be prepared by GPS from benzyl halide. (Fits) 3. From H3C−CONH2: Product is Methylamine (H3C−NH2). Methylamine is a primary amine and can be prepared by GPS from methyl halide. (Fits) 6. From H11C6−CONH2: Product is Hexylamine (H11C6−NH2). Hexylamine is a primary amine and can be prepared by GPS from hexyl halide. (Fits) Therefore, compounds 2, 3, and 6 satisfy both conditions. The total number of such compounds is 3.

💡 Teacher's Secret Hint

Gabriel Phthalimide Synthesis is limited to primary alkyl amines and does not work for aryl or branched amines.

✦ STEM Console utilizes AI models to generate step-by-step explanations and math clues. AI can make mistakes.