When phenol is treated with excess bromine water, it produces

Analysis of the reaction products of phenol with excess bromine water

in the chemical reaction, the reaction of phenol and bromine water is a typical organic reaction, which is often used in the detection and analysis of phenol. Especially when phenol is reacted with an excess of bromine water, the reaction produces some characteristic products. This article will analyze in detail the reaction products and their related reaction mechanisms when phenol is treated with excess bromine water.

Phenol and bromine water reaction basis

Phenol (C; H; OH) is an aromatic compound with a hydroxyl group. The hydroxyl group in its molecular structure has a strong electron supply effect on the benzene ring, making the benzene ring more active. Bromine water (Br₂ aqueous solution) is a strong oxidant, commonly used for the bromination of organic compounds. When phenol reacts with bromine water, the bromine molecules in the bromine water will undergo electrophilic substitution reactions with the benzene ring.

Excess Bromine Water on Phenol Reaction

When phenol reacts with bromine water, if the amount of bromine water is too much, the bromine molecules in the bromine water will continue to participate in the reaction, resulting in further bromination of the benzene ring. Generally speaking, phenol will undergo a monobromination reaction in the initial stage to produce bromophenol (CHH4 BrOH), which is the product of the reaction of phenol with a bromine atom. However, under the condition of excess bromine water, multiple positions on the benzene ring may be brominated, and finally the brominated product is formed.

Main reaction products

1. 2,4, 6-Tribromophenol: This is one of the main products of the reaction of phenol with excess bromine water. The hydroxyl group in the phenol molecule has a strong electron donating effect, especially at the ortho and para positions, resulting in easy addition of bromine molecules to these positions of the benzene ring. Therefore, the 2, 4, 6 positions of the benzene ring are most easily brominated, eventually forming tribromophenol.

2. Multiple bromination caused by excessive bromine in bromine water: When the amount of bromine water is too much, phenol will not only be brominated at the 2, 4, and 6 positions, but also brominated at other positions of the benzene ring, resulting in the production of more Brominated products, such as dibromophenol or other types of bromophenol.

reaction mechanism analysis

The reaction mechanism of phenol with excess bromine water is usually an electrophilic aromatic substitution reaction. Bromine molecules in bromine water will be oxidized to bromide ions (Br), bromide ions and phenol in the benzene ring electrophilic substitution reaction, the formation of bromophenol. In the case of excess bromine water, the reaction will continue until multiple positions of the benzene ring are replaced by bromine atoms, thereby forming brominated products such as tribromophenol.

Reaction of the application and significance

The reaction of phenol with excess bromine water is commonly used in the laboratory to identify and detect the presence of phenol. The bromophenol or tribromophenol produced in the reaction is a method for qualitative detection of phenol, and this reaction has high experimental application value in organic chemistry. In particular, the reaction of phenol with bromine water is very useful when measuring the concentration of phenol or analyzing phenol derivatives.

Summary

When phenol is treated with excess bromine water, the major product it will produce is 2,4, 6-tribromophenol. This reaction can not only help us understand the reaction characteristics of phenol, but also widely used in the qualitative analysis of phenol. By controlling the amount of bromine water, the reaction process can be effectively adjusted to obtain different degrees of brominated products. Therefore, it is of great significance to master the reaction mechanism of phenol and bromine water for chemical research and experimental operation.