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Halogenation of benzene where X is the halogen, catalyst represents the catalyst (if needed) and HX represents the protonated base. A few types of aromatic compounds, such as phenol, will react without a catalyst, but for typical benzene derivatives with less reactive substrates, a Lewis acid is required as a catalyst.
The ferric chloride test is used to determine the presence of phenols in a given sample or compound (for instance natural phenols in a plant extract). Enols, hydroxamic acids, oximes, and sulfinic acids give positive results as well. [1]
In chemistry, halogenation is a chemical reaction which introduces one or more halogens into a chemical compound. Halide-containing compounds are pervasive, making this type of transformation important, e.g. in the production of polymers, drugs. [1] This kind of conversion is in fact so common that a comprehensive overview is challenging.
The overall reaction mechanism, denoted by the Hughes–Ingold mechanistic symbol S E Ar, [3] begins with the aromatic ring attacking the electrophile E + (2a). This step leads to the formation of a positively charged and delocalized cyclohexadienyl cation, also known as an arenium ion, Wheland intermediate, or arene σ-complex (2b).
In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. [1] [2] [3] Phenolic compounds are produced by plants and microorganisms. [4] Organisms sometimes synthesize phenolic compounds in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. [5]
A tetrachlorophenol is any organochloride of phenol that contains four covalently bonded chlorine atoms. Tetrachlorophenols are produced by electrophilic halogenation of phenol with chlorine. [1] Different isomers of tetrachlorophenol exist according to which ring positions on the phenol contain chlorine atoms. There are three different isomers:
A study shows that vegans are at greater risk of being depressed because of milk alternatives they choose. But a Washington, D.C., doctor has some concerns about the new findings.
Phenol is a component in liquid–liquid phenol–chloroform extraction technique used in molecular biology for obtaining nucleic acids from tissues or cell culture samples. Depending on the pH of the solution either DNA or RNA can be extracted. Phenol is so inexpensive that it also attracts many small-scale uses.