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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.
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, the ability to recycle the hydrogen chloride made the Raschig–Hooker process preferable to the Dow and Bayer process, which requires its sodium chloride product to be ...
Accounting for 95% of production (2003) is the cumene process, also called Hock process. It involves the partial oxidation of cumene (isopropylbenzene) via the Hock rearrangement: [8] Compared to most other processes, the cumene process uses mild conditions and inexpensive raw materials. For the process to be economical, both phenol and the ...
When 1-[14 C]-1-chlorobenzene was subjected to aqueous NaOH at 395 °C, ipso substitution product 1-[14 C]-phenol was formed in 54% yield, while cine substitution product 2-[14 C]-phenol was formed in 43% yield, indicating that an elimination-addition (benzyne) mechanism is predominant, with perhaps a small amount of product from addition ...
The Dow process may refer to: Dow process (bromine), a method of bromine extraction from brine; Dow process (magnesium), a method of magnesium extraction from brine; Dow process (phenol), a method of phenol production through the hydrolysis of chlorobenzene
At one time, chlorobenzene was the main precursor for the manufacture of phenol: [10] C 6 H 5 Cl + NaOH → C 6 H 5 OH + NaCl. The reaction is known as the Dow process, with the reaction carried out at 350 °C using fused sodium hydroxide without solvent.
Antione Bechamp described a process for reducing nitrobenzene to aniline in 1854, known as the Bechamp Process, making the production of aniline easy. [12] Widespread isolation of phenol from coal tar, made its nitration more economical, generally the path of the synthesis flowed: coal tar → nitrobenzene → aniline → dyes. [13]
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: