What catalyst is used for a nitration reaction?
Nitration is an important chemical reaction widely used in commercial manufacturing of various nitro-aromatics. Concentrated H2SO4 has been currently used as the most effective and efficient catalyst in a large-scale liquid phase nitration process.
What is the mechanism of nitration of phenol?
There are 2 processes of nitration of phenol: (i)- With dilute nitric acid: When dilute nitric acid at 293 K is used, phenols give mononitrophenols i.e., a mixture of 2-nitrophenol and 4-nitrophenol. Nitro molecule (NO2) is an electrophile. The nitro group is attached to the phenol by removing the hydrogen atom.
Which reagent is used in the nitration process?
nitric acid
The key reagent for nitration is nitric acid, HNO3. By itself, nitric acid is a relatively slow-acting electrophile, especially in the presence of a poor nucleophile such as benzene. [Note – in the case of phenol and other aromatic rings with strongly activating groups, HNO3 by itself is sufficient for nitration].
What is the major product of nitration of phenol?
ortho-nitrophenol
Nitration of phenol with dilute nitric acid give the mixture of ortho-nitrophenol and para-nitrophenol. But the major product is ortho-nitrophenol(30%–40%). Since it is an electrophilic aromatic substitution reaction.
Is sulfuric acid a catalyst for nitration?
The concentrated sulfuric acid is acting as a catalyst.
Why is sulfuric acid used in nitration?
Sulfuric acid is needed in order for a good electrophile to form. Sulfuric acid protonates nitric acid to form the nitronium ion (water molecule is lost). The nitronium ion is a very good electrophile and is open to attack by benzene. Without sulfuric acid the reaction would not occur.
Which chemicals can react with phenol?
Phenol is a good nucleophile, meaning it likes to donate electrons, and therefore can form a chemical bond in reactions. Phenol can react with acetyl chloride and acetic anhydride to form esters. Esters are when one or more OH (hydroxyl) groups are replaced by an O-alkyl (alkoxy) group.
What happen when phenol is treated with nitrating mixture?
Complete step-by-step answer:When nitrating mixture reacts with Phenol, it produces the isomers of phenol i.e. p-nitrophenol and o-nitrophenol. There is an introduction of the nitro group at ortho position and para position.
How do you make phenol?
In this method, benzene sulfonic acid is reacted with aqueous sodium hydroxide. The resulting salt is mixed with solid sodium hydroxide and reacted at a high temperature. The product of this reaction is sodium phenoxide, which is acidified with aqueous acid to make phenol.
What happens when phenol undergoes nitration?
Phenols upon treatment with dilute nitric acid undergo nitration at low temperature (298 K) to give a mixture of ortho and para nitrophenols. When phenol is treated with concentrated nitric acid, the nitration results in the formation of 2, 4, 6-trinitrophenol (commonly called picric acid).
How is phenol nitrated over solid acid catalyst?
Phenol is nitrated selectively by dilute nitric acid over alumina and a remarkable ortho-selectivity is observed in liquid phase nitration. Highlights i. The solid acid catalyst (Gamma-alumina) was prepared by control precipitation method. ii. Phenol was selectively nitrated in liquid phase using dilute nitric acid (30%) in presence γ-alumina. iii.
Are there any nitrating reagents for nitration of phenols?
]. However, some of the nitrating reagents are poorly regioselective and uneconomical. Considering these concerns, there is still a good scope for research towards finding economic, mild reagents for regioselective nitration of phenols. Melamine is a widely used fire retarder in polymers.
Which is the nitration product of phenol over alumina?
The ortho-nitrophenol which is a major product of nitration reaction used for synthesis of valuable compounds. Some of these methods have contributed significantly for enhancing the scope of nitration reaction but very little work has been done on the region selectivity of phenol over alumina as a catalyst [15].
What is the ratio of nitrophenol to phenol?
It is found from the previous study that the nitration of phenol using a mixture of nitric and sulfuric acid gives 2-nitrophenol and 4-nitrophenol in a ratio of 1.42 [1]. The limitation of this process lies in the use of corrosive liquid mixture of nitric and sulfuric acid which produce large amounts of wastes.