The major product P formed in the following sequence of reactions… — Solution | JEE Chemistry

MCQMediumJEE 2023Carboxylic Acids

The major product $P$ formed in the following sequence of reactions is:

Answer

Correct answer:D

Standard Method

Given: The substrate is subjected to $\text{SOCl}_2$ , then $\text{R-NH}_2$ , then $\text{LiAlH}_4$ , followed by $\text{H}_3\text{O}^+$ .

Find: The major product $P$ after the full reaction sequence.

The sequence proceeds stepwise:

$\text{SOCl}_2$ converts the carboxylic acid group $-\text{COOH}$ into an acyl chloride $-\text{COCl}$ .
Reaction with $\text{R-NH}_2$ converts the acyl chloride into the amide $-\text{CONHR}$ .
$\text{LiAlH}_4$ reduces the amide $-\text{CONHR}$ to the amine $-\text{CH}_2\text{NHR}$ .
$\text{H}_3\text{O}^+$ gives the acidic workup and protonates the intermediate.

Therefore, the final product contains $-\text{CH}_2\text{NHR}$ . The correct option is D.

The solution states option (4) as the final product, even though one header shows C. From the reaction working, option (4) is chemically correct.

Treating $\text{SOCl}_2$ as if it directly reduces the acid is incorrect. It converts $-\text{COOH}$ to $-\text{COCl}$ . First identify the functional group interconversion before tracking the next reagent.
Stopping at the amide $-\text{CONHR}$ is a common mistake. $\text{LiAlH}_4$ does not leave the amide unchanged; it reduces it further to $-\text{CH}_2\text{NHR}$ .
Choosing the option based only on the inconsistent label in the provided header is wrong. The reaction mechanism shown in the explanation is the reliable basis, so the product must be the reduced amine.

Get unlimited AI-adaptive practice, mastery tracking, and an AI tutor that explains every step — free to start.