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The term stems from cumene (isopropyl benzene), the intermediate material during the process. It was invented by R. Ūdris and P. Sergeyev in 1942 (USSR), [1] and independently by Heinrich Hock in 1944. [2] [3] This process converts two relatively cheap starting materials, benzene and propylene, into two more valuable ones, phenol and acetone.
[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 ...
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]
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 ...
Acetophenone is formed as a byproduct of the cumene process, the industrial route for the synthesis of phenol and acetone.In the Hock rearrangement of isopropylbenzene hydroperoxide, migration of a methyl group rather than the phenyl group gives acetophenone and methanol as a result of an alternate rearrangement of the intermediate:
Dow process (phenol), a method of phenol production through the hydrolysis of chlorobenzene Topics referred to by the same term This disambiguation page lists articles associated with the title Dow process .
It is a flammable colorless liquid that has a boiling point of 152 °C. Nearly all the cumene that is produced as a pure compound on an industrial scale is converted to cumene hydroperoxide, which is an intermediate in the synthesis of other industrially important chemicals, primarily phenol and acetone (known as the cumene process).
After exposure to 63 to 405 mg/m 3 of benzene for 1 to 5 hours, 51 to 87% was excreted in the urine as phenol over a period of 23 to 50 hours. In another human study, 30% of absorbed dermally applied benzene, which is primarily metabolized in the liver, was excreted as phenol in the urine.