AIIMS2019Chemistry-Organic Chemistry

AIIMS 2019 Chemistry Reaction Mechanisms MCQ Question

Type: MCQ-conceptual-Hard-Class 11

APhSO2ClBKOHCC2H5ID\text{A} \xrightarrow{\text{Ph}-\text{SO}_2\text{Cl}} \text{B} \xrightarrow{\text{KOH}} \text{C} \xrightarrow{\text{C}_2\text{H}_5\text{I}} \text{D}'C' is water solubleCorrect structure of A and D are

A

RNH2 , PhSO2NR(C2H5)2+I\text{R} - \text{NH}_2 \text{ , } \text{Ph} - \text{SO}_2 - \text{NR} - (\text{C}_2\text{H}_5)_2^+ \text{I}^-

B

RNHR , PhSO2NR2C2H5\text{R} - \text{NH} - \text{R} \text{ , } \text{Ph} - \text{SO}_2 - \text{NR}_2 - \text{C}_2\text{H}_5

C

RNH2 , PhSO2NRI\text{R} - \text{NH}_2 \text{ , } \text{Ph} - \text{SO}_2 - \text{NR} - \text{I}

D

R2NH , PhSO2NR2(C2H5)+I\text{R}_2\text{NH} \text{ , } \text{Ph} - \text{SO}_2 - \text{NR}_2 - (\text{C}_2\text{H}_5)^+ \text{I}^-

Correct Answer

Option B

Detailed Explanation

Option B is correct because it contains a primary amine (R – NH – R) and a sulfonium ion (Ph – SO₂ – NR₂ – C₂H₅), which allows for the formation of a water-soluble compound. Primary amines are more likely to engage in hydrogen bonding with water, enhancing solubility. In contrast, option A features a quaternary ammonium ion, which is less soluble in water, while options C and D do not provide the necessary structure for water solubility due to the presence of either an iodide or a tertiary amine, which limits solubility in polar solvents like H₂O.

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