Several questions about the reaction of phenol with bromine

The first question is that NaHSO3 is a reducing agent, and the purpose of the lotion is not to identify, and the purpose is not to separate or remove impurities, so here is to reduce 2,4,4,6-tetrabromo-2,5-cyclohexadienone to tribromophenol.

The second question, 2,4,4,6-tetrabromo-2,5-cyclohexadieneone, in terms of structure, double bonded oxygen and so much bromine, the charge density is very sparse, then the bromine is easy to leave as a positive ion. The structural characteristics of phenol derivatives are that the first class of substituents of benzene is an electron-pushing group, which must be electrophilic substitution, and it is easy to produce bromocation, which is of course suitable for bromination.

The third question is that the Girard reagent is divided into Girard-T and Girard-PGirard-T is trimethylaminoacetylhydrazide chloride.

Girard-p is py+ pyridinium.

Both of these are used to isolate ketones.

In general, if you want to identify it, you can add bromine water to the phenol, and the bromine water must be a small amount, and it will not go further, and the more phenol itself is reducible. In addition, you yourself said in the second question that 2,4,4,6-tetrabromo-2,5-cyclohexadiene can also be used as a bromination reagent for aniline and phenol derivatives, therefore, in the case of phenol excess, 2,4,4,6-tetrabromo-2,5-cyclohexadiene will not exist, and the white precipitate is obvious. Therefore, if you want to identify it, you can add it dropwise directly.

The last two upstairs are explained more clearly, and there is no more nonsense.

What is the reaction of phenol with bromine water, and the reaction of phenol with bromine water belongs to the substitution reaction to generate tribromophenol.

The reaction of phenol with bromine water is a substitution reaction to produce tribromophenol. Phenol (C6H5OH) is a colorless needle-like crystal with a special odor, which is toxic and is an important raw material for the production of certain resins, fungicides, preservatives, and drugs such as aspirin. It can also be used for disinfection of surgical instruments and excrement treatment, **sterilization, anti-itching and otitis media.

Substitution reaction refers to the reaction in which any atom or atomic group in a compound or organic molecule is replaced by other atoms or atomic groups of the same type in the reagent, which is expressed by the general formula: r l (reaction matrix) + a-b (attack reagent) r a (substitute product) + l-b (leaving group) belongs to a class of chemical reactions.

The phenol with bromine reaction is a classical organic chemical reaction that involves a chemical reaction between phenol and bromine compounds. According to the chemical equation, phenol and bromine can be used to produce 2-bromophenol. During this reaction, phenol and bromine compounds undergo an electrophilic substitution reaction.

Although this reaction is not particularly complex, it can be used to illustrate some important chemical principles.

In this reaction, the bromine compound acts as a photophile as it has a positive charge. When phenol comes into contact with a bromine compound, the bromine ions are released from the bromine compound and then form a covalent chemical bond with the negatively charged hydrogen atom in the phenol. This process causes the hydrogen ions in the phenol molecules to be removed, making them negative ions.

Then, one of these negative ions attacks the other bromine atom in the bromorean ion, thus forming 2-bromophenol.

Phenol is an aromatic compound that has important applications in many ways. It can be used as a biocide and disinfectant, and is also widely used in the manufacture of dyes and medicines. In addition, phenol can also be converted into compounds such as benzaldehyde and benzoic acid through oxidation reactions.

Overall, the reaction of phenol with bromine is one of the basic reactions that are widely used in the field of chemistry. Through this reaction, we can learn important principles about electrophilic substitution reactions and chemical bond formation. In addition, this reaction has a wide range of practical applications and in-depth research.

1. The equation for the reaction of phenol and bromine water.

1.Reaction equation: C h OH + 3BR ==C h ohBR +3HBR

2.Reaction phenomenon: A small amount of phenol solution is dropped into concentrated bromine water, and a white precipitate appears immediately, and can then turn into a yellow precipitate. Because phenol is added to concentrated bromine water, tribromophenol white precipitate is generated, and excessive bromine water dissolves in wild god sun tribromophenol, which is yellow!

3.Note that this phenomenon should be caused by dropping a small amount of phenol deficiency in concentrated bromine water! (If there is an excess of phenol, only a white precipitate will appear.) )

A small amount of bromine water was dropped into the phenol solution, and only a white precipitate appeared.

2. Health hazards of phenol.

Phenol has a strong corrosive effect on ** and mucous membranes, which can inhibit the central nervous system or damage liver and kidney function. Acute poisoning: Inhalation of high-concentration vapors can cause headache, dizziness, fatigue, blurred vision, pulmonary edema, etc.

Accidental ingestion causes burns of the digestive tract, burning pain, phenolic smell of exhaled air, vomit or stool can carry blood, there is the possibility of gastrointestinal perforation, shock, pulmonary edema, liver or kidney damage, acute renal failure, and death from respiratory failure. <>

The reaction of phenol (C6H5OH) and bromine (Br2) is a very typical redox reaction.

In the chemical equation, the redox state of octacitol changes from "0" to "+1", while the redox state of bromine changes from "0" to "-1".

When phenol reacts with bromine, it first changes the redox state from "0" to "+1" through electron transfer, forming cations and bromine intermediates of phenol.

This intermediate then reacts with the phenol molecule to produce 1-bromophenol, which simultaneously releases hydrogen ions (H+).

This reaction can be expressed by the chemical equation as: C6H5OH+BR2 C6H5O+BR-+H+ C6H5BR+HBR From the equation, it can be seen that bromine (BR2) acts as an oxidant in the reaction, changing the redox state of phenol from "0" to "+1", while the formed bromine ion (BR-) combines with phenol cation to form 1-bromophenol (C6H5BRroh).

At the same time, a hydrogen ion is released during the reduction process, forming a molecule of HBR.

The reaction between phenol and bromine is a typical redox reaction, which forms phenol cations and bromine intermediates through electron transfer and ion coordination, and then further forms 1-bromophenol with phenol molecules.

This reaction can be used not only for routine research in laboratory mold purification, but also for some chemical reaction processes in industrial production. <>

The substitution of phenol and bromine reacts to form 2,4,6 tribromophenol, which displaces H on the metasite.

C6H5OH+3BR2===2, 4,6 tribromophenol +3HBR. A small amount of phenol solution is dropped into concentrated bromine water, and the white precipitate is immediately detected out of the panicle, and it can then turn into a yellow precipitate.

Properties of Phenol:

1. Reducibility of phenol.

Phenol is a colorless crystal, but it will be exposed to the air for a long time and oxidized by oxygen to give it a pink color.

2. Weak acidity of phenol.

Phenol is extremely acidic and cannot discolor the acid-base indicator, so the presence of phenol cannot be tested with a code indicator.

3. Phenol substitution reaction.

Phenol and bromine water are easy to substitute reaction, the phenomenon is obvious, can be used for the detection of phenol, can also be used for the quantitative detection of phenol content in domestic wastewater.

4. Chromogenic reaction of phenol.

A small amount of FeCl3 solution was added dropwise to the phenol solution, and the color of the solution was purple. This reaction can be used to test for the presence of phenol, but not for the isolation or purification of phenol. <>

Phenol and bromine undergo a substitution reaction in the presence of a strong acid catalyst, which usually requires the use of lewis acid or proton acid, such as formic acid, sulfuric acid, ferrous chloride, etc. When a strong acid is present, the hydrogen ions on the hydroxyl group will be replaced by protons in the acid to form an intermediate, and then the bromine ions in the brominating agent will react with the intermediate, and the hydroxyl group in the molecule will be replaced by bromine to form phenyl bromide. Phenylbromide plays an important role in many organic synthesis, such as the preparation of other compounds, the synthesis of drugs, the preparation of chemical reagents, etc.

Factors such as the chemical properties of phenol and brominating agents involved in the reaction, the reaction temperature, the reaction time, etc., will affect the efficiency and results of the reaction. Therefore, chemistry researchers need to optimize experimental conditions for higher reaction yields and purity. In addition to brominating agents, chlorinating agents and iodizing agents can also replace brominating agents, producing different substitution products.

In general, the substitution reaction of phenol with high bromine is an important organic chemical reaction. This reaction has a wide range of applications and can be used to prepare many chemicals, as well as to help understand the mechanism of chemical reactions and other basic knowledge of organic chemistry. <>

Summary. C6H5OH+3BR2 2,4,6 Tribromophenol +3HBR. The reaction of phenol with concentrated bromine water produces 2,4,6 tribromophenol and hydrobromic acid, which is a substitution reaction.

Chemical equation.

C6H5OH+3BR2 2,4,6 Tritard-Returned Bromophenol +3HBR. The reaction of phenol with concentrated bromine water will produce 2,4,6 tribromophenol and bibronic acid in hydrocelery, which is a substitute reaction.