The correct set(s) of reactions to synthesize benzoic acid starting from benzene is/are
- (i)Br2/Fe (ii)Mg/dry ether (iii)CO2 (iv)H3O⨁
- (i)Br2/Fe (ii)NH3,25°C (iii)NaNO2,dil. HCl, 0° to 5°C (iv)CuCN/KCN (v)dil.HCl,△
- (i)CH3Cl,Anhydrous AlCl3 (ii)KMnO4|⨁OH,△ (iii)H3O⨁
- (i)CH3COCl,Anhydrous AlCl3 (ii)Br2,NaOH (iii)H3O⨁
The Correct Option is A, C, D
Solution and Explanation
Goal: Convert benzene (C₆H₆) into benzoic acid (C₆H₅COOH)
Option (A):
- (i) Br₂/Fe → Bromination: C₆H₆ → C₆H₅Br
- (ii) Mg/dry ether → Grignard reagent formation: C₆H₅Br → C₆H₅MgBr
- (iii) CO₂ → Carboxylation: C₆H₅MgBr + CO₂ → C₆H₅COOMgBr
- (iv) H₃O⁺ → Acid workup: C₆H₅COOMgBr + H₃O⁺ → C₆H₅COOH (benzoic acid)
Option (C):
- (i) CH₃Cl + Anhyd. AlCl₃ → Friedel–Crafts Alkylation: C₆H₆ → C₆H₅CH₃ (toluene)
- (ii) KMnO₄ / OH⁻ / Δ → Side-chain oxidation: C₆H₅CH₃ → C₆H₅COO⁻
- (iii) H₃O⁺ → Acidification: C₆H₅COO⁻ + H₃O⁺ → C₆H₅COOH
Option (D):
- (i) CH₃COCl + Anhyd. AlCl₃ → Friedel–Crafts Acylation: C₆H₆ → C₆H₅COCH₃ (acetophenone)
- (ii) Br₂, NaOH → Haloform reaction: C₆H₅COCH₃ → C₆H₅COO⁻
- (iii) H₃O⁺ → Acidification: C₆H₅COO⁻ + H₃O⁺ → C₆H₅COOH
Final Answer:
Correct option(s): (A), (C), and (D)
Top Questions on Aldehydes, Ketones and Carboxylic Acids
- Would you expect benzaldehyde to be more reactive or less reactive in nucleophilic addition reactions than propanal? Justify your answer.
- CBSE CLASS XII - 2025
- Chemistry
- Aldehydes, Ketones and Carboxylic Acids
- The acid formed when propyl magnesium bromide is treated with CO$_2$ followed by acid hydrolysis is:
- CBSE CLASS XII - 2025
- Chemistry
- Aldehydes, Ketones and Carboxylic Acids
Convert Ethanal to But-2-enal
- CBSE CLASS XII - 2025
- Chemistry
- Aldehydes, Ketones and Carboxylic Acids
- Which of the following reagents is used in Rosenmund reduction?
- MHT CET - 2025
- Chemistry
- Aldehydes, Ketones and Carboxylic Acids
- When benzene is treated with carbon monoxide and hydrogen chloride in the presence of anhydrous aluminium chloride, benzaldehyde is formed. The reaction is known as
- KEAM - 2025
- Chemistry
- Aldehydes, Ketones and Carboxylic Acids
Questions Asked in WBJEE exam
- Let \( f(\theta) = \begin{vmatrix} 1 & \cos \theta & -1 \\ -\sin \theta & 1 & -\cos \theta \\ -1 & \sin \theta & 1 \end{vmatrix} \). Suppose \( A \) and \( B \) are respectively the maximum and minimum values of \( f(\theta) \). Then \( (A, B) \) is equal to:
- If \( a, b, c \) are in A.P. and if the equations \( (b - c)x^2 + (c - a)x + (a - b) = 0 \) and \( 2(c + a)x^2 + (b + c)x = 0 \) have a common root, then
- WBJEE - 2025
- Quadratic Equations
- If \( g(f(x)) = |\sin x| \) and \( f(g(x)) = (\sin \sqrt{x})^2 \), then:
- WBJEE - 2025
- Functions
- Which logic gate is represented by the following combination of logic gates?
- WBJEE - 2025
- Logic gates
- Ruma reached the metro station and found that the escalator was not working. She walked up the stationary escalator with velocity \( v_1 \) in time \( t_1 \). On another day, if she remains stationary on the escalator moving with velocity \( v_2 \), the escalator takes her up in time \( t_2 \). The time taken by her to walk up with velocity \( v_1 \) on the moving escalator will be:
- WBJEE - 2025
- Relative Motion
Concepts Used:
Aldehydes, Ketones, and Carboxylic Acids
Aldehydes, Ketones, and Carboxylic Acids are carbonyl compounds that contain a carbon-oxygen double bond. These organic compounds are very important in the field of organic chemistry and also have many industrial applications.
Aldehydes:
Aldehydes are organic compounds that have the functional group -CHO.
Preparation of Aldehydes
Acid chlorides are reduced to aldehydes with hydrogen in the presence of palladium catalyst spread on barium sulfate.
Ketones:
Ketones are organic compounds that have the functional group C=O and the structure R-(C=O)-R’.
Preparation of Ketones
Acid chlorides on reaction with dialkyl cadmium produce ketones. Dialkyl cadmium themselves are prepared from Grignard reagents.
Carboxylic Acid:
Carboxylic acids are organic compounds that contain a (C=O)OH group attached to an R group (where R refers to the remaining part of the molecule).
Preparation of Carboxylic Acids
Primary alcohols are readily oxidized to carboxylic acids with common oxidizing agents such as potassium permanganate in neutral acidic or alkaline media or by potassium dichromate and chromium trioxide in acidic media.