Nitration is a a general chemical process for the introduction of a nitro group into a chemical compound. In a " scientific " sense a chemical process is a method or means of somehow changing one or more Chemicals or Chemical compounds Such a chemical Nitro compounds are Organic compounds that contain one or more nitro Functional groups (-2 A chemical compound is a substance consisting of two or more different elements chemically bonded together in a fixed proportion by Mass. Examples of nitrations are the conversion of glycerin to nitroglycerin and the conversion of toluene to trinitrotoluene. Nitroglycerin ( NG) ( US spelling also known as nitroglycerine, ( UK Spelling trinitroglycerin, trinitroglycerine Toluene, also known as methylbenzene or phenylmethane, is a clear water -insoluble liquid with the typical smell of Paint thinners redolent of Trinitrotoluene ( TNT) is a Chemical compound with the formula C6H2(NO23CH3 Both of these conversions use nitric acid and sulfuric acid. Nitric acid ( H[[nitrate NO3]] also known as Aqua fortis and spirit of nitre, is a highly corrosive and Sulfuric (or sulphuric acid, H 2 S[[oxygen O]]4 is a strong Mineral acid.

Aromatic nitration

In "aromatic nitration," aromatic organic compounds are nitrated via an electrophilic aromatic substitution mechanism involving the attack of the electron-rich benzene ring by the nitronium ion. Electrophilic aromatic substitution or EAS is an Organic reaction in which an atom usually Hydrogen, appended to an aromatic system is replaced Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6 The nitronium ion (improperly called nitryl ion, because it is not a radical 2+ is a generally unstable Cation created by the removal of an Alternative mechanisms have also been proposed, as the one involving single electron transfer (SET)^[1][2]. Aromatic nitro compounds are important intermediates to anilines by action of a reducing agent. Aniline, phenylamine or aminobenzene is an Organic compound with the formula C6H7N A reducing agent (also called a reductant or reducer) is the element or a compound in a Redox (reduction-oxidation reaction (see Electrochemistry Benzene is nitrated by refluxing with concentrated sulfuric acid and concentrated nitric acid at 50 °C.

2 H₂SO₄ + HNO₃ → 2 HSO₄^- + NO₂⁺ + H₃O⁺

C₆H₆ + NO₂⁺ → C₆H₅NO₂ + H⁺

H⁺ + H₃O⁺ + 2 HSO₄^- → H₂O + 2H₂SO₄

The sulfuric acid is regenerated and hence acts as a catalyst. Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst It also absorbs water.

Nitration of benzene

The formation of a nitronium ion (the electrophile) from nitric acid and sulfuric acid is shown below:

Reaction of nitric acid and sulfuric acid

Scope

Selectivity is always a challenge in nitrations, The nitration of fluorenone is selective and yields a tri-nitro compound^[3] or tetra-nitro compound ^[4] by modifying reaction conditions. Fluorenone is an Aromatic Organic compound with the chemical formula C13H8O Another example of trinitration can be found in the synthesis of phloroglucinol. Phloroglucinol or benzene-135-triol is a process chemical widely used in the industrial synthesis of pharmaceuticals and high-energy chemicals ( Explosives

Other nitration reagents include nitronium tetrafluoroborate, a nitronium salt. Tetrafluoroborate is the Anion BF4− This tetrahedral species is Isoelectronic with many stable and important species including tetrafluoromethane This compound can be prepared from hydrogen fluoride, nitric acid, and boron trifluoride. Structure HF forms orthorhombic crystals consisting of zig-zag chains of HF molecules Nitric acid ( H[[nitrate NO3]] also known as Aqua fortis and spirit of nitre, is a highly corrosive and Boron trifluoride is the Chemical compound with the formula BF3 ^[5]

The substituents on aromatic rings affect the rate of this electrophilic aromatic substitution. The reaction rate or rate of reaction for a Reactant or product in a particular reaction is intuitively defined as how fast a reaction takes Electrophilic aromatic substitution or EAS is an Organic reaction in which an atom usually Hydrogen, appended to an aromatic system is replaced Deactivating groups such as other nitro groups have an electron-withdrawing effect. In Organic chemistry, a deactivating group is a Functional group attached to a Benzene Molecule that removes Electron density from Such groups deactivate (slow) the reaction and directs the electrophilic nitronium ion to attack the aromatic meta position. Arene substitution patterns are part of Organic chemistry IUPAC nomenclature and pinpoint the position of Substituents other than Hydrogen in Deactivating meta-directoring substituents include sulfonyl, cyano groups, keto, esters, and carboxylates. A sulfonyl group is an organic radical or Functional group obtained from a Sulfonic acid by the removal of the Hydroxyl group A cyanide is any Chemical compound that contains the cyano group (C≡N which consists of a Carbon Atom triple-bonded to a A ketone (pronounced as key tone) is either the Functional group characterized by a Carbonyl group (O=C linked to two other Carbon atoms or Esters are a class of Chemical compounds and Functional groups Esters consist of an inorganic or organic Acid in which at least A carboxylate anion is an Ion with Negative charge that contains the group -COO&minus Nitration can be accelerated by activating groups such as amino, hydroxy and methyl groups also amides and ethers resulting in para and ortho isomers. In Organic chemistry, a Functional group is called an activating group if a Benzene Molecule to which it is attached more readily participates Amines are Organic compounds and Functional groups that contain a basic Nitrogen Atom with a Lone pair. In Chemistry, a methyl group is a Hydrophobic Alkyl Functional group named after Methane (4 In Chemistry, an amide is one of three kinds of Compounds (sometimes called acid amide the organic Functional group characterized Ether is a class of Organic compounds which contain an ether group — an Oxygen Atom connected to two (substituted Alkyl

The direct nitration of aniline with nitric acid and sulfuric acid, according to one source ^[6] results in a 50/50 mixture of para and meta nitroaniline. Aniline, phenylamine or aminobenzene is an Organic compound with the formula C6H7N In this reaction the fast-reacting and activating aniline (ArNH₂) is in equilibrium with the more abundant but less reactive and deactivating anilinium ion (ArNH₃⁺), which may explain this reaction product distribution. According to another source ^[7] a more controlled nitration of aniline starts with the formation of acetanilide by reaction with acetic anhydride followed by the actual nitration. Acetanilide is an odourless Solid chemical of leaf or flake-like appearance Acetic anhydride is the Chemical compound with the formula (CH3CO2O Because the amide is a regular activating group the products formed are the para and ortho isomers. Heating the reaction mixture is sufficient to hydrolyze the nitroamide back to the nitroamine.

In the Wolfenstein-Boters reaction, benzene reacts with nitric acid and mercury nitrate to give picric acid. Benzene, or benzol, is an organic Chemical compound and a known Carcinogen with the molecular formula C 6 H 6

References