Question:
Predict the product (B) in the following sequence of reactions
\[
\text{Ethylbenzene} \xrightarrow{KMnO_4 / KOH} A \xrightarrow{H_3O^+} B
\]
Predict the product (B) in the following sequence of reactions
\[
\text{Ethylbenzene} \xrightarrow{KMnO_4 / KOH} A \xrightarrow{H_3O^+} B
\]
Show Hint
KMnO$_4$ converts any alkyl benzene → benzoic acid (if benzylic H present).
Updated On: May 2, 2026
- Benzaldehyde
- Benzophenone
- Benzene
- Acetophenone
- Benzoic acid
Show Solution
Verified By Collegedunia
The Correct Option is
Solution and Explanation
Concept: Oxidation of alkyl side chain in benzene
---
Step 1: Understand the reagent
KMnO$_4$ in alkaline medium is a strong oxidizing agent. Key rule:
• Any alkyl side chain attached to benzene (with at least one benzylic H) is oxidized to COOH. ---
Step 2: Identify substrate
Ethylbenzene = C$_6$H$_5$–CH$_2$CH$_3$ It has benzylic hydrogens → oxidation possible. ---
Step 3: Oxidation reaction
\[ C_6H_5-CH_2CH_3 \xrightarrow{KMnO_4/KOH} C_6H_5COOK \] Intermediate A = potassium benzoate ---
Step 4: Acidification
\[ C_6H_5COOK \xrightarrow{H_3O^+} C_6H_5COOH \] Product B = Benzoic acid --- Final Answer: \[ \boxed{\text{Benzoic acid}} \]
---
Step 1: Understand the reagent
KMnO$_4$ in alkaline medium is a strong oxidizing agent. Key rule:
• Any alkyl side chain attached to benzene (with at least one benzylic H) is oxidized to COOH. ---
Step 2: Identify substrate
Ethylbenzene = C$_6$H$_5$–CH$_2$CH$_3$ It has benzylic hydrogens → oxidation possible. ---
Step 3: Oxidation reaction
\[ C_6H_5-CH_2CH_3 \xrightarrow{KMnO_4/KOH} C_6H_5COOK \] Intermediate A = potassium benzoate ---
Step 4: Acidification
\[ C_6H_5COOK \xrightarrow{H_3O^+} C_6H_5COOH \] Product B = Benzoic acid --- Final Answer: \[ \boxed{\text{Benzoic acid}} \]
Was this answer helpful?
0
0
Top KEAM Chemistry Questions
- The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
- $4\, g$ of copper was dissolved in concentrated nitric acid. The copper nitrate solution on strong heating gave $5\, g$ of its oxide. The equivalent weight of copper is :
- Green chemistry deals with
- Neopentyl bromide undergoes dehydrohalogenation to give alkenes even though it has no $\beta$- hydrogen. This is due to
- Plot of $ log\text{ }x/m $ against log $p$ is a straight line inclined at an angle of $ 45{}^\circ $ . When the pressure is $ 0.5 \,arm $ and Freundlich parameter. $ k $ is $ 10 $ , the amount of solute adsorbed per gram of adsorbent will be $ (log\text{ }5=0.6990) $
View More Questions
Top KEAM Aldehydes, Ketones and Carboxylic Acids Questions
- When a mixture of benzaldehyde and acetophenone is treated with dilute $NaOH$ at $293\, K$, it forms
- Which of the following pairs can be distinguished by sodium hypoiodite?
- The following reaction is named as
- The compound which does not lead to benzoic acid by oxidation with $KMnO_4$ is
- Benzonitrile can be prepared from benzaldehyde on treatment with
View More Questions
Top KEAM Questions
- i.$\quad$ They help in respiration ii.$\quad$ They help in cell wall formation iii.$\quad$ They help in DNA replication iv. $\quad$They increase surface area of plasma membrane Which of the following prokaryotic structures has all the above roles?
- A body oscillates with SHM according to the equation (in SI units), $x = 5 cos \left(2\pi t +\frac{\pi}{4}\right) .$ Its instantaneous displacement at $t = 1$ second is
- The pH of a solution obtained by mixing 60 mL of 0.1 M BaOH solution at 40m of 0.15m HCI solution is
Kepler's second law (law of areas) of planetary motion leads to law of conservation of
- If $\int e^{2x}f' \left(x\right)dx =g \left(x\right)$, then $ \int\left(e^{2x}f\left(x\right) + e^{2x} f' \left(x\right)\right)dx =$
View More Questions