Why is the yield of nitration of phenol low?

Phenols are usually nitrated with a mixture of nitric and sulfuric acids . This latter reaction leads, however, to poor yields of the nitrated derivatives because of the oxidation of the phenols to quinoid products.

Why does nitration of phenol give picric acid?

Nitration of phenol involve reaction with NO+2 Nitronium ion which is a electrophile. Therefore , it is electrophilic substitution reaction.

How does the nitration of phenol with dilute nitric acid differ from nitration of phenol with concentrated nitric acid in the presence of Sulphuric acid?

The reaction of phenol with nitric acid is a mono-nitration reaction i.e. Only one hydrogen atom gets replaced per molecule of phenol. The reaction of phenol with concentrated nitric acid in the presence of sulphuric acid, however, is a tri-nitration reaction. …

What does the nitration of phenol give?

An example of an Electrophilic substitution reaction is the 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.

Why does phenol show electrophilic aromatic substitution explain with special reference to nitration of phenol?

Phenols are highly prone to electrophilic substitution reactions due to rich electron density. The hydroxyl group attached to the aromatic ring in phenol facilitates the effective delocalization of the charge in the aromatic ring. Thus, it stabilizes the arenium ion through resonance.

When phenol react with dilute nitric acid it yields product as?

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 (common name: picric acid).

What is the use of sulphuric acid in nitration process?

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.

What is the role of Sulphuric acid in the 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.

How does phenol react with nitric acid?

Can phenol react with 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, more nitro groups substitute around the ring to give 2,4,6-trinitrophenol (old name: picric acid).

Why phenol goes electrophilic substitution more easily than benzene?

Electron donating group increases the electron density at ortho and para position of a benzene ring and so increases the rate of electrophilic substitution reaction. As oxocation is more stable than carbocation so phenol undergoes electrophilic substitution more easily than benzene.

Why phenol goes electrophilic substitution reaction?

What happens when phenol is treated with nitric acid?

When phenol is treated with concentrated nitric acid, the nitration results in the formation of 2, 4, 6-trinitrophenol (commonly called picric acid).

How do you make picric acid from phenol?

In this reaction nitration is accompanied by oxidation of phenol. Industrially, picric acid is prepared by treating phenol, first with concentrated H 2 SO 4 which converts it to phenol-2,4-disulphuric acid.

Why picric acid is stronger acid than p-nitro phenol?

Picric acid also forms CT complex known as picrates , with aromatic hydrocarbons, amines and phenols. Why p-nitro phenol is stronger acid than m-nitro phenol? The strength of acid depends on the stability of the concern anion of that acid . The anion of both acid stabilized through resonance.

What is picric acid and what is its nature?

What is picric acid? why 2,4,6 tri-nitro phenol is called picric acid? 2,4,6-tri-nitro phenol is generally known as picric acid. It is a very strong organic acid. 2,4,6-trinitro phenol contains three strong electron withdrawing nitro group.