Advanced Topic 783 of 1102 Organic Chemistry
Nitration of Benzene
Reaction with nitric and sulfuric acid mixture gives nitrobenzene.
In-depth explanation of Nitration of Benzene
Nitration of benzene is an electrophilic aromatic substitution in which a mixture of concentrated nitric and sulfuric acids generates the nitronium ion, NO2+. Sulfuric acid protonates nitric acid, which then loses water to produce the nitronium ion, the electrophile that attacks the benzene ring. The reaction is carried out at about 50 degrees Celsius, since higher temperatures promote dinitration and other side reactions. The product, nitrobenzene, is an important intermediate because reduction converts it into aniline, a precursor of many dyes and drugs.
Going deeper: Nitration of Benzene
Key ideas: Use a nitrating mixture of concentrated HNO3 and concentrated H2SO4 at 50 to 55 C to give nitrobenzene; above 60 C dinitration occurs, mainly meta. Sulfuric acid protonates nitric acid, giving NO2+ (nitronium ion), the true electrophile. Nitro groups reduce to amines with Sn and HCl or H2 over Ni, giving aniline.
Common mistakes and connections: Students name HNO3 as the electrophile or forget that H2SO4 is a catalyst that is regenerated. Another mistake is nitrating aniline directly: the amine is protonated to anilinium (a meta director), so acetylate first. Links to directing effects, aniline synthesis, dyes and explosives such as TNT.
Visualization of Nitration of Benzene
Benzene is attacked by the nitronium ion NO2+ made from HNO3 and H2SO4, giving nitrobenzene after loss of a proton. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Nitrobenzene is reduced with tin and hydrochloric acid, or with hydrogen and a catalyst, to give aniline.
Frequently asked questions about Nitration of Benzene
What is Nitration of Benzene?
Reaction with nitric and sulfuric acid mixture gives nitrobenzene.
Is Nitration of Benzene a beginner, intermediate or advanced topic?
Nitration of Benzene is a advanced topic in Organic Chemistry. It builds on beginner and intermediate topics, so review those first if needed.
What should I learn before Nitration of Benzene?
Study these earlier topics in Organic Chemistry first: Ozonolysis, Polymerization of Alkenes, Electrophilic Aromatic Substitution.
What comes after Nitration of Benzene?
The next topics in Organic Chemistry are Friedel-Crafts Reactions and Directing Effects.
Can I practise Nitration of Benzene with quizzes?
Yes. The interactive lesson includes a self-check question on Nitration of Benzene, and the Organic Chemistry quiz draws on every topic in this area.
Where Nitration of Benzene fits in Organic Chemistry
Nitration of Benzene is topic 55 of 148 in Organic Chemistry.