What is halogenation nitration Sulphonation?
Nitration and sulfonation of benzene are two examples of electrophilic aromatic substitution. The nitronium ion (NO2+) and sulfur trioxide (SO3) are the electrophiles and individually react with benzene to give nitrobenzene and benzenesulfonic acid respectively.
What is the product of nitration?
During nitration, the nitronium ion is formed when nitric acid undergoes a reaction with sulfuric acid. Nitronium serves as an electrophile which is attacked by the nucleophilic benzene ring. The resulting product of nitration is nitrobenzene.
What is the major product of nitration of phenol?
Phenoxide ion undergoes electrophilic substitution with carbon dioxide ( a weak electrophile) because phenoxide ion is more reactive than phenol. Salicylic acid is formed as a major product.
How phenol is activated nucleus for nitration?
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.
Why dilute sulphuric acid is added in nitration of phenol?
In the protonation of nitric acid by sulfuric acid, the source of the nitronium ion induces the removal of a water molecule and the creation of a nitronium ion. The first step in benzene nitration is to activate HNO3 with sulfuric acid to create a nitronium ion, a stronger electrophile.
What reagent is sulphonation?
Answer: fuming sulphuric acid is used as a reagent in sulphonation reaction. Explanation: Sulphonation:- Basically Sulfonation is a reaction of benzene with fuming sulphuric acid , in this process benzene is heated with fuming sulphuric acid that gives benzenesulfonic acid and the nature of this reaction is reversible.
What is the major product formed in the nitration of phenol?
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. In which Nitric acid (HNO3) is an electrophile and benzene ring is an nucleophile.
What is the major product in nitration of phenol with dilute nitric acid?
When phenol is treated with dilute nitric acid at room temper ed with dilute nitric acid at room temperature a mixture of o-nitron p-nitrophenol is obtained and o-nitrophenol is major product.
Why is para product major?
Usually, when an ortho-para directing substituent is present for an electrophilic aromatic replacement reaction on the benzene ring, the para product is the main product except when the COOH group’s hydrogen bonding or ortho effect renders the ortho product a significant one.
What is electrophile in nitration of phenol?
The attacking species in nitration reaction is nitronium ion which is an electrophile. Hence the reaction is called as electrophilic substitution.
What happens when phenol reacts with h2so4?
When phenol reacts with concentrated sulphuric acid, Phenol reacts with sulfuric acid giving substituted phenols. At room temperature an equilibrium is established between a mixture of phenol sulphuric acid and the product benzene ortho hydroxy sulfuric acid.
When phenol reacts with conc h2so4 hno3 The major product formed is?
The reaction of phenol with concentrated nitric acid in the presence of sulphuric acid, however, is a tri-nitration reaction. the product is 2,4,6-trinitrophenol (commonly called picric acid).
What is the use of nitration of phenol compounds?
Use of Nitration of phenol compounds is an important chemical process that has wide applications in dyes, pharmaceuticals, Scheme 1. Traditional Nitration of Phenol agrochemicals, explosives, and plastic industry.
What happens when Phenol reacts with nitric acid?
With dilute nitric acid Phenol reacts with dilute nitric acid at room temperature to give a mixture of 2-nitrophenol and 4-nitrophenol. With concentrated nitric acid With concentrated nitric acid, more nitro groups substitute around the ring to give 2,4,6-trinitrophenol (old name: picric acid).
How do you convert phenoxy radicals to nitrophenols?
They have proposed a mechanism in which the phenoxy radical is the key intermediate. In this mechanism the first step is an electron transfer with NO + as the transfer agent, followed by a deprotonation step leading to the phenoxy radical which than reacts with nitrogen dioxide to give the nitrophenols (Scheme 2).
What is the chemical name of phenol?
This page looks at the structure and physical properties of phenol (very old name: carbolic acid). Phenol is the simplest member of a family of compounds in which an -OH group is attached directly to a benzene ring.