Cumene route phenol synthesis

The first totally synthetic route to a solvent in the United States was the synthesis of isopropyl alcohol from propylene by Melco Chemical Corporation in 1917. In 1928 Union Carbide made acetone from isopropyl alcohol the synthesis of acetone in the cumene-to-phenol process came much later and now is the source of about 85% of acetone production. In 1927 Du Pont began the synthesis of methanol. Synthetic ethyl alcohol was made from ethylene by Union Carbide in 1929. Specialized books on ethyl alcohol (14. 15) and isopropyl alcohol (16) give many details on the manufacture, properties, and uses of these major products. 

The specifications for the quality of phenol are based on its downstream application. The phenol content is generally over 99%, the water content below 0.1%. For 8-caprolactam and bisphenol A production, only a low level of carbonyl compounds is in fact tolerable. The nature of by-products accordingly depends on the respective synthesis route. Phenol produced from cumene contains acetophenone and a-methylstyrene as co-products. Phenol manufactured by the Raschig method contains small amounts of chlorophenol tar phenols contain minor proportions of nitrogen and sulfur components. 

Phenol is a petrochemical derived from benzene and propylene by the cumene route, and formaldehyde is obtained by the oxidation of methanol which in turn is derived from synthesis gas. Until the 1950s, phenol, as extracted from coal tar by distillation, was contaminated with cresols and xylenols. 

With worldwide phenol consumption exceeding 5 million tons in 1995, optimizing production routes of this essential chemical becomes very important. As an alternative to the traditional cumene process, a one-step-synthesis of phenol from benzene is highly desirable. With a ZSM5 type zeolite in its acid form as catalyst and nitrous oxide as oxidant, benzene may be directly oxidized to phenol [1-4] ... 

Nowadays, synthetic vanUlm is obtained predominantly from petrochemical sources. For vanillin, the key compound is guaiacol (o-methoxyphenol). This is obtained initially from wood tar, coal tar, wood distillate or lignite distillate. Targeted syntheses start from benzene via dichlorobenzene, catechol may be obtained, which is further monomethylated. The second route begins with the oxidation of cumene (the so called Hock synthesis ) to give phenol, and continues with nitration, methylation, reduction, diazotisation and heating of the diazonium salt solution. [142]... 

Phenol is one of the most important intermediates of the chemical industry. The global capacity for its production was around 10 Mt/y in 2008, with an actual production around 8.7 Mt. About 40% of the produced phenol is used for the synthesis of bisphenol A, a monomer for polycarbonates. Another 30% is consumed in the production of phenolic resins. The most important route for the industrial production of phenol is, by far, the cumene process, which accounts for 98% of the installed capacity. The cumene process is based upon the researches of Heinrich Hock on the... 

While the diazonium salt route is probably the most commonly used laboratory synthesis of phenols, phenol itself is manufactured from wo-propylbenzene, which has the common name cumene. Cumene is prepared by a Friedel-Crafts reaction between propene and benzene, in the presence of a strong acid such as H3PO4 (Figure 13.28). The key intermediate is the 2-propyl cation, formed by protonation of propene. 

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