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Mya Sweetman
10/12/2025
Chemistry
The reactions of benzene and its derivatives
64
•
10 Dec 2025
•
Mya Sweetman
@myasweetman_1603
Understanding how benzene reacts with different chemicals is absolutely crucial... Show more
Benzene might seem intimidating, but it really only undergoes a handful of key reactions that you need to master. The most important ones are nitration, halogenation (bromination and chlorination), alkylation, and acylation.
All these reactions follow the same basic pattern called electrophilic substitution. This means an electrophile attacks the benzene ring and replaces one of the hydrogen atoms. The benzene ring stays intact throughout - that's what makes it so stable.
What's brilliant about these reactions is that they're all interconnected. You can convert benzene to nitrobenzene, then reduce that to phenylamine, and phenylamine reacts completely differently with halogens than benzene does.
Remember: Benzene is so stable that it needs harsh conditions or catalysts to react - this stability is key to understanding why these reactions work the way they do.
Nitration transforms benzene into nitrobenzene using concentrated nitric acid and sulfuric acid at exactly 50°C. The sulfuric acid acts as a catalyst, creating the nitronium ion (NO₂⁺) which is the actual electrophile that attacks the benzene ring.
Keep that temperature at 50°C - go higher and you'll get unwanted dinitrobenzene products. The mechanism involves the nitronium ion accepting electrons from the benzene ring, forming an unstable intermediate that quickly reforms the stable benzene structure with the nitro group attached.
Halogenation (bromination and chlorination) won't happen unless you use a halogen carrier catalyst like FeBr₃ or AlCl₃. These catalysts create the electrophile - for bromine, it's the bromonium ion (Br⁺) that actually does the attacking.
The beauty of these reactions is that the catalyst gets regenerated at the end, so you only need small amounts. Without the catalyst, benzene is simply too stable to react with bromine or chlorine.
Top tip: Always remember that benzene needs help to react - whether it's heat and acid for nitration or metal halide catalysts for halogenation.
Friedel-Crafts alkylation lets you stick alkyl groups onto benzene using haloalkanes and AlCl₃ catalyst. This reaction is incredibly useful because it creates new carbon-carbon bonds, allowing you to build more complex molecules from simple starting materials.
For example, benzene plus ethyl chloride (C₂H₅Cl) with AlCl₃ gives you ethylbenzene. The AlCl₃ helps generate the electrophile that attacks the benzene ring, just like in halogenation reactions.
Acylation reactions work similarly but use acyl chlorides instead of haloalkanes. When benzene reacts with ethanoyl chloride (CH₃COCl) and AlCl₃, you get phenylethanone - a compound actually used in the perfume industry.
Both these reactions are examples of electrophilic substitution and follow the same three-step mechanism: catalyst generates electrophile, electrophile attacks benzene, catalyst regenerates.
Real-world connection: Acylation products like phenylethanone are used commercially in perfumes and other consumer products - chemistry you can actually smell!
Here's where things get interesting - phenylamine (C₆H₅NH₂) behaves completely differently from benzene when it comes to reactions. You make phenylamine by reducing nitrobenzene using tin and concentrated hydrochloric acid, followed by treatment with excess sodium hydroxide.
The reduction process actually goes through two steps: first forming the ammonium salt (phenylammonium chloride), then converting that to the free amine with NaOH. This two-step process is essential for getting pure phenylamine.
Once you've got phenylamine, it's incredibly reactive compared to benzene. While benzene needs a catalyst to react with bromine, phenylamine reacts rapidly with bromine water at room temperature, giving multiple substitution products.
This dramatic difference in reactivity happens because the amino group activates the benzene ring, making it much more electron-rich and attractive to electrophiles.
Exam insight: Questions often test the contrast between benzene's reluctance to react and phenylamine's eagerness - understanding this difference is worth serious marks.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
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Anna
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Best app on earth! no words because it’s too good
Thomas R
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Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
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This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Mya Sweetman
@myasweetman_1603
Understanding how benzene reacts with different chemicals is absolutely crucial for organic chemistry at A-level. These reactions follow predictable patterns and mechanisms that you can master with practice, giving you the tools to tackle synthesis questions with confidence.
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Benzene might seem intimidating, but it really only undergoes a handful of key reactions that you need to master. The most important ones are nitration, halogenation (bromination and chlorination), alkylation, and acylation.
All these reactions follow the same basic pattern called electrophilic substitution. This means an electrophile attacks the benzene ring and replaces one of the hydrogen atoms. The benzene ring stays intact throughout - that's what makes it so stable.
What's brilliant about these reactions is that they're all interconnected. You can convert benzene to nitrobenzene, then reduce that to phenylamine, and phenylamine reacts completely differently with halogens than benzene does.
Remember: Benzene is so stable that it needs harsh conditions or catalysts to react - this stability is key to understanding why these reactions work the way they do.
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Nitration transforms benzene into nitrobenzene using concentrated nitric acid and sulfuric acid at exactly 50°C. The sulfuric acid acts as a catalyst, creating the nitronium ion (NO₂⁺) which is the actual electrophile that attacks the benzene ring.
Keep that temperature at 50°C - go higher and you'll get unwanted dinitrobenzene products. The mechanism involves the nitronium ion accepting electrons from the benzene ring, forming an unstable intermediate that quickly reforms the stable benzene structure with the nitro group attached.
Halogenation (bromination and chlorination) won't happen unless you use a halogen carrier catalyst like FeBr₃ or AlCl₃. These catalysts create the electrophile - for bromine, it's the bromonium ion (Br⁺) that actually does the attacking.
The beauty of these reactions is that the catalyst gets regenerated at the end, so you only need small amounts. Without the catalyst, benzene is simply too stable to react with bromine or chlorine.
Top tip: Always remember that benzene needs help to react - whether it's heat and acid for nitration or metal halide catalysts for halogenation.
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Friedel-Crafts alkylation lets you stick alkyl groups onto benzene using haloalkanes and AlCl₃ catalyst. This reaction is incredibly useful because it creates new carbon-carbon bonds, allowing you to build more complex molecules from simple starting materials.
For example, benzene plus ethyl chloride (C₂H₅Cl) with AlCl₃ gives you ethylbenzene. The AlCl₃ helps generate the electrophile that attacks the benzene ring, just like in halogenation reactions.
Acylation reactions work similarly but use acyl chlorides instead of haloalkanes. When benzene reacts with ethanoyl chloride (CH₃COCl) and AlCl₃, you get phenylethanone - a compound actually used in the perfume industry.
Both these reactions are examples of electrophilic substitution and follow the same three-step mechanism: catalyst generates electrophile, electrophile attacks benzene, catalyst regenerates.
Real-world connection: Acylation products like phenylethanone are used commercially in perfumes and other consumer products - chemistry you can actually smell!
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Here's where things get interesting - phenylamine (C₆H₅NH₂) behaves completely differently from benzene when it comes to reactions. You make phenylamine by reducing nitrobenzene using tin and concentrated hydrochloric acid, followed by treatment with excess sodium hydroxide.
The reduction process actually goes through two steps: first forming the ammonium salt (phenylammonium chloride), then converting that to the free amine with NaOH. This two-step process is essential for getting pure phenylamine.
Once you've got phenylamine, it's incredibly reactive compared to benzene. While benzene needs a catalyst to react with bromine, phenylamine reacts rapidly with bromine water at room temperature, giving multiple substitution products.
This dramatic difference in reactivity happens because the amino group activates the benzene ring, making it much more electron-rich and attractive to electrophiles.
Exam insight: Questions often test the contrast between benzene's reluctance to react and phenylamine's eagerness - understanding this difference is worth serious marks.
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
You can download the app from Google Play Store and Apple App Store.
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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Explore the detailed mechanisms of acylation reactions in organic chemistry, focusing on acyl chlorides and acid anhydrides. This summary covers nucleophilic addition-elimination processes, hydrolysis reactions, and the formation of carboxylic acids and amides. Ideal for AQA A Level Chemistry students seeking to understand the intricacies of organic mechanisms.
ChemistryExplore the reactivity and mechanisms of benzene and phenol, including electrophilic substitution reactions, delocalization of electrons, and key comparisons between alkenes and arenes. This summary covers essential concepts such as nitration, halogenation, and Friedel-Crafts reactions, providing a comprehensive understanding for students studying aromatic compounds.
ChemistryExplore key organic reaction mechanisms including electrophilic addition, electrophilic substitution, and nucleophilic substitution. This summary covers the reactions of alkenes, benzene, carbonyl compounds, and halogenoalkanes, detailing reactants, products, and conditions necessary for each mechanism. Ideal for OCR A-level chemistry students.
ChemistryExplore the key mechanisms of electrophilic and nucleophilic reactions in benzene, including Friedel-Crafts acylation and alkylation. This summary covers essential organic reactions and their mechanisms, tailored for A-Level Chemistry students, particularly those following the OCR B Salters syllabus.
ChemistryExplore the key concepts of aromatic chemistry, including the structure and reactivity of benzene, electrophilic substitution mechanisms, and the role of delocalized electrons. This summary covers nitration and Friedel-Crafts reactions, comparing the reactivity of alkenes and arenes, and the unique properties of phenols. Ideal for A-Level organic chemistry students.
ChemistryExplore the mechanisms of nucleophilic substitution reactions in haloalkanes, including hydrolysis processes and bond enthalpy. This summary covers primary, secondary, and tertiary haloalkanes, common nucleophiles, and environmental impacts of organohalogen compounds. Ideal for A Level organic chemistry students.
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE THE SCHOOLGPT. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Sociology