Electrophilic aromatic substitution: mechanism and directing effects

55 questions on Electrophilic aromatic substitution: mechanism and directing effects from the Organic Reaction Mechanisms II: Electrophilic and Radical Reactions chapter: 11 NEET level, 22 JEE Main, 22 JEE Advanced. Each one opens with its answer and solution.

• In the nitration of benzene with a mixture of concentrated HNO3 and concentrated H2SO4, the attacking electrophile is NEET level
• The cationic intermediate formed when an electrophile attacks benzene in electrophilic aromatic substitution is called NEET level
• Which of the following groups is meta directing in electrophilic aromatic substitution? NEET level
• Which of the following compounds is the most reactive towards electrophilic aromatic substitution? NEET level
• Nitration of toluene with HNO3 and H2SO4 gives mainly NEET level
• The chlorine atom in chlorobenzene is NEET level
• Benzene reacts with CH3Cl in the presence of anhydrous AlCl3 to give mainly NEET level
• Friedel-Crafts alkylation fails with NEET level
• In the sulfonation of benzene with fuming sulfuric acid, the electrophile is NEET level
• In electrophilic aromatic substitution of benzene, the rate-determining step is NEET level
• Benzene reacts with CH3COCl and anhydrous AlCl3 to give NEET level
• Heating nitrobenzene with concentrated HNO3 and concentrated H2SO4 gives mainly JEE Main level
• Which of the following correctly gives the decreasing order of rate of nitration? JEE Main level
• Anisole is treated with Br2 in ethanoic acid (no catalyst). The major product is JEE Main level
• Benzene reacts with 1-chloropropane in the presence of anhydrous AlCl3. The major product is JEE Main level
• Benzoic acid is treated with Br2 and FeBr3. The major product is JEE Main level
• Aniline does not undergo Friedel-Crafts alkylation or acylation because JEE Main level
• Halogens are deactivating yet ortho/para directing in electrophilic aromatic substitution because JEE Main level
• The nitration of benzene-d6 (C6D6) proceeds at almost the same rate as that of C6H6. This shows that JEE Main level
• Nitration of tert-butylbenzene with HNO3 and H2SO4 gives mainly JEE Main level
• Benzenesulfonic acid is heated with steam in dilute sulfuric acid. The main organic product is JEE Main level
• Acetanilide (C6H5NHCOCH3) is nitrated with HNO3 in H2SO4 at low temperature. The major product is JEE Main level
• Assertion (A): Nitrobenzene does not undergo Friedel-Crafts reaction. Reason (R): The -NO2 group strongly deactivates the benzene ring towards electrophilic att... JEE Main level
• p-CH3-C6H4-OCH3 (4-methylanisole) is nitrated under mild conditions with dilute HNO3. The major mononitration product is JEE Main level
• Which one of the following gives only one mononitro product (constitutional isomer) on nitration of the ring? JEE Main level
• Which sequence of reactions converts benzene mainly into 1-bromo-3-nitrobenzene? JEE Main level
• Benzene is treated successively with (i) CH3CH2CH2COCl, anhydrous AlCl3 and (ii) Zn(Hg), conc. HCl. The final product is JEE Main level
• Consider the following ring substituents on benzene: -F, -Cl, -OH, -NHCOCH3, -NO2, -CN, -Br, -CH3, -COOH, -I. Count how many of them are both ortho/para directi... JEE Main level
• Which of the following substituents are ortho/para directing in electrophilic aromatic substitution? JEE Main level
• Under the usual Friedel-Crafts conditions (alkyl or acyl chloride with anhydrous AlCl3) which of the following compounds do NOT react? JEE Main level
• Which statements about the sulfonation of benzene with fuming sulfuric acid are correct? JEE Main level
• Which of the following react with nitrating mixture faster than benzene does? JEE Main level
• Which statements about the arenium ion intermediate in electrophilic aromatic substitution are correct? JEE Main level
• 4-Nitrotoluene is brominated with Br2 and FeBr3 (ring bromination). The major product is JEE Advanced level
• 4-Methylphenol (p-cresol) is treated with dilute HNO3 at low temperature. The major mononitration product is JEE Advanced level
• Which route converts benzene into 4-nitrobenzoic acid (as the major product at the aromatic stage, ignoring separation of minor isomers)? JEE Advanced level
• Which sequence converts benzene mainly into 1-bromo-3-ethylbenzene? JEE Advanced level
• Benzene is treated with 1-chloro-2,2-dimethylpropane ((CH3)3C-CH2Cl) and anhydrous AlCl3. The major product is JEE Advanced level
• Benzene is treated with 1-chloro-2-methylpropane ((CH3)2CH-CH2Cl) and anhydrous AlCl3. The major product is JEE Advanced level
• Phenol is treated with one equivalent of Br2 in CS2 at 0 degC. The major product is JEE Advanced level
• Which of the following correctly gives the decreasing order of rate of nitration? JEE Advanced level
• Electrophilic attack on anisole is faster at the para position than at the meta position mainly because JEE Advanced level
• The meta product dominates in the nitration of nitrobenzene mainly because JEE Advanced level
• Toluene must be converted mainly into 2-nitrotoluene while avoiding the para isomer. Which sequence uses the sulfonic acid group as a blocking group? JEE Advanced level
• Chlorobenzene is heated with excess HNO3 and H2SO4 until dinitration occurs. The major dinitration product is JEE Advanced level
• Assertion (A): Treating benzene with excess CH3Cl and AlCl3 gives polymethylbenzenes, whereas excess CH3COCl and AlCl3 gives only acetophenone. Reason (R): A me... JEE Advanced level
• Match the substituents on benzene (List I) with their effect in electrophilic aromatic substitution (List II). List I: P -OCH3; Q -Cl; R -COCH3; S -CH3. List II... JEE Advanced level
• 1,3-Dimethoxybenzene is treated with CH3COCl and anhydrous AlCl3. The major product is JEE Advanced level
• The partial rate factors for nitration of toluene (relative to one position of benzene) are f_o = 42, f_m = 2.5 and f_p = 58. Remember that toluene has two orth... JEE Advanced level
• Which of the following compounds give only ONE mononitration product (counting constitutional isomers formed by replacing one ring hydrogen)? JEE Advanced level
• In which of the following reactions is the major ring-substituted product the meta isomer? JEE Advanced level
• Which statements about Friedel-Crafts reactions of benzene are correct? JEE Advanced level
• Which statements about the generation of electrophiles are correct? JEE Advanced level
• For nitration of tert-butylbenzene compared with benzene and toluene, which statements are correct? JEE Advanced level
• For electrophilic attack on anisole, which statements about the arenium ions are correct? JEE Advanced level