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Via the Hock rearrangement, cyclohexylbenzene hydroperoxide cleaves to give phenol and cyclohexanone. Cyclohexanone is an important precursor to some nylons. [8] Starting with the alkylation of benzene with mixture of 1 and 2-butenes, the cumene process produces phenol and butanones. [5]
[6] [7] Due to the two step nature, the Raschig–Hooker process can be used to produce either chlorobenzene or phenol. Reaction scheme of the Raschig-Hooker process. The Raschig–Hooker process's ability to make phenol makes it comparable to other methods, such as the Dow and Bayer process, which also converts benzene into phenol. In fact ...
Phenol is reduced to benzene when it is distilled with zinc dust or when its vapour is passed over granules of zinc at 400 °C: [22] C 6 H 5 OH + Zn → C 6 H 6 + ZnO. When phenol is treated with diazomethane in the presence of boron trifluoride (BF 3), anisole is obtained as the main product and nitrogen gas as a byproduct. C 6 H 5 OH + CH 2 N ...
Benzene can be easily converted to chlorobenzene by nucleophilic aromatic substitution via a benzyne intermediate. [1] It is treated with aqueous sodium hydroxide at 350 °C and 300 bar or molten sodium hydroxide at 350 °C to convert it to sodium phenoxide, which yields phenol upon acidification. [2]
Many phenols of commercial interest are prepared by elaboration of phenol or cresols. They are typically produced by the alkylation of benzene/toluene with propylene to form cumene then O 2 is added with H 2 SO 4 to form phenol (Hock process). In addition to the reactions above, many other more specialized reactions produce phenols:
Benzene is sufficiently nucleophilic that it undergoes substitution by acylium ions and alkyl carbocations to give substituted derivatives. Electrophilic aromatic substitution of benzene. The most widely practiced example of this reaction is the ethylation of benzene. Approximately 24,700,000 tons were produced in 1999. [73]
Reaction of benzene with propylene to give cumene in the presence of phosphoric acid supported on silica and promoted with boron trifluoride. Since the mid-1990s, commercial production has switched to zeolite-based catalysts. In this process, the efficiency of cumene production is generally 70-75%.
The Dakin oxidation is an organic redox reaction in which an ortho- or para-hydroxylated phenyl aldehyde (−CH=O) or ketone (>C=O) reacts with hydrogen peroxide in base to form a benzenediol and a carboxylate. Overall, the carbonyl group (C=O) is oxidized, and the hydrogen peroxide is reduced.