Search results
Results From The WOW.Com Content Network
In the case of nitration of benzene, the reaction is conducted at a warm temperature, not exceeding 50 °C. [6] The process is one example of electrophilic aromatic substitution, which involves the attack by the electron-rich benzene ring: Alternative mechanisms have also been proposed, including one involving single electron transfer (SET). [7 ...
The nitration of benzene is achieved via the action of the nitronium ion as the electrophile. The sulfonation with fuming sulfuric acid gives benzenesulfonic acid. Aromatic halogenation with bromine, chlorine, or iodine gives the corresponding aryl halides. This reaction is typically catalyzed by the corresponding iron or aluminum trihalide.
The Wolffenstein–Böters reaction is an organic reaction converting benzene to picric acid by a mixture of aqueous nitric acid and mercury(II) nitrate. [1] [2] [3]The reaction, which involves simultaneous nitration and oxidation, was first reported by the German chemists Richard Wolffenstein and Oskar Böters in 1906.
Electrophilic substitution reactions are chemical reactions in which an electrophile displaces a functional group in a compound, which is typically, but not always, aromatic. Aromatic substitution reactions are characteristic of aromatic compounds and are common ways of introducing functional groups into benzene rings.
Nitrobenzene is prepared by nitration of benzene with a mixture of concentrated sulfuric acid, water, and nitric acid. This mixture is sometimes called "mixed acid." The production of nitrobenzene is one of the most dangerous processes conducted in the chemical industry because of the exothermicity of the reaction (ΔH = −117 kJ/mol). [5] +
In nitration, benzene reacts with nitronium ions (NO 2 +), which is a strong electrophile produced by combining sulfuric and nitric acids. Nitrobenzene is the precursor to aniline . Chlorination is achieved with chlorine to give chlorobenzene in the presence of a Lewis acid catalyst such as aluminium tri-chloride.
The nitration product produced on the largest scale, by far, is nitrobenzene. Many explosives are produced by nitration including trinitrophenol (picric acid), trinitrotoluene (TNT), and trinitroresorcinol (styphnic acid). [3] Another but more specialized method for making aryl–NO 2 group starts from halogenated phenols, is the Zinke nitration.
The EWG removes electron density from a π system, making it less reactive in this type of reaction, [2] [3] and therefore called deactivating groups. EDGs and EWGs also determine the positions (relative to themselves) on the aromatic ring where substitution reactions are most likely to take place.