Phenols industrial synthesis

The most widely used industrial synthesis of phenol is based on isopropylbenzene (cumene) as the starting material and is shown m the third entry of Table 24 3 The eco nomically attractive features of this process are its use of cheap reagents (oxygen and sulfuric acid) and the fact that it yields two high volume industrial chemicals phenol and acetone The mechanism of this novel synthesis forms the basis of Problem 24 29 at the end of this chapter... 

A Methylamino)phenol. This derivative (15) is easily soluble ia ethyl acetate, ethanol, diethyl ether, and benzene. It is also soluble ia hot water, but only spatingly soluble ia cold water. Industrial synthesis is by heating 3-(A/-methylamino)benzenesulfonic acid with sodium hydroxide at 200—220°C (179) or by the reaction of resorciaol with methylamiae ia the presence of aqueous phosphoric acid at 200°C (180). 

A A Diethylamino)phenol. This derivative (16) forms rhombic bipyramidal crystals. Industrial synthesis is analogous to the previously described synthesis of 3-(/V,/V-dimethy1amino)pheno1 from resorciaol and diethylamiae, by reaction of 3-(Ai,A/-diethylamiQo)benzenesulfonic acid with sodium hydroxide, or by alkylation of 3-amiaophenol hydrochloride with ethanol. 

A Methylamino)phenol. This derivative, also named 4-hydroxy-/V-methy1ani1ine (19), forms needles from benzene which are slightly soluble in ethanol andinsoluble in diethyl ether. Industrial synthesis involves decarboxylation of A/-(4-hydroxyphenyl)glycine [122-87-2] at elevated temperature in such solvents as chlorobenzene—cyclohexanone (184,185). It also can be prepared by the methylation of 4-aminophenol, or from methylamiae [74-89-5] by heating with 4-chlorophenol [106-48-9] and copper sulfate at 135°C in aqueous solution, or with hydroquinone [123-31 -9] 2l. 200—250°C in alcohoHc solution (186). 

KOLBE - SCHMIDT Salicylic Acid Synthesis Caiboxylation (usually ortho) of phenols. Industrial method to obtain salicylic acid derivatives... 

An important industrial synthesis of cyclohexanone is by partial hydrogenation of phenol over palladium, carried out in either liquid or vapor phase. 

Phenols occur widely throughout nature and also serve as intermediates in the industrial synthesis of products as diverse as adhesives and antiseptics. Phenol itself is a general disinfectant found in coal tar methyl salicylate is a flavoring agent found in oil of wintergreen and the urushiols are the allergenic constituents of poison oak and poison ivy. Note that the word phenol is the name both of the specific compound hydroxybenzene and of a class of compounds. 

The most widely used industrial synthesis of phenol is based on isopropylbenzene can you recall howto pre-... 

Recently, a copper-catalyzed synthesis of trimethyl- 1,4-benzoquinone, a key intermediate in the industrial synthesis of vitamin E, has been reported (Eq. 11) [49]. In the proposed mechanism, a tetranuclear cluster [Cu4(a -O)Cl10], isolated from the reaction mixture, deprotonates phenol and oxidizes it to a copper-bound phenolate radical, which reacts with dioxygen. 

Disinfection by-product) production of urea-formaldehyde, phenolic, melamine, pentaerythritol and polyacetal resins industrial synthesis of a number of organic compounds cosmetics fungicides textiles embalming fluids 3210,322, 351, 3529,354... 

Autoxidation of cumene (2.61) is the most important industrial synthesis of cumene hydroperoxide (2.62), which gives phenol and acetone. 

The method has proved to be valuable for the synthesis of basic thio-phenols in industrial synthesis, as shown by the manufacture of the starting material dimethylthiocarbamoyl chloride [104]. 

Autoxidation is one of the key steps in the industrial synthesis of phenol and acetone from benzene and propylene. In the second step of this synthesis, cumene (isopropylbenzene) is autoxidized to give cumyl hydroperoxide. 

Many simple alcohols are important raw materials in the industrial synthesis of polymers, fibers, explosives, plastics, and pharmaceutical products. Phenols are widely used in the preparation of plastics and dyes. Solutions of phenols are used as antiseptics and disinfectants. Some uses of polyhydric alcohols depend on their relatively high boiling points. For instance, glycerine is used as a wetting agent in cosmetic preparations. Ethylene glycol (bp 197°C), which is miscible with water, is used in commercial permanent antifreeze. 

While the autoxidation of hydrocarbons is of paramount importance to the industrial synthesis of several bulk chemicals [2b, 14] including phenol (Scheme 3) [14a], it is rarely used as a preparative method in the laboratory [7a]. 

The first step in the industrial synthesis of aspirin is known as the Kolbe-Schmitt carboxylation reaction. The phenolate ion reacts with carbon dioxide under pressure to form o-hydroxybenzoic acid, also known as salicylic acid. Acetylation of salicylic acid with acetic acid forms acetylsalicylic acid (aspirin). 

All the methods for the industrial synthesis of phenol with the exception of... 

The most recent processes particularly for the industrial synthesis of catechol and hydroquinone are by the direct hydroxylation of phenol at SOX with 70% hydrogen peroxide solution in the presence of catalytic quantities of strong mineral acids, such as perchloric acid, with ferrous sulphate (Fenton s reagent) or cobaltous sulphate (ref.35). The organic products are solvent extracted and fractionated to separate the two products from the starting material. With a ferrous catalyst, resorcinol accompanies the two main products. 

The transformation of the seven-membered ring lactone into an ether and the deoxygenation of the phenol both have extensive literature precedent. Once this is successful, we will then have prepared an advanced intermediate in the industrial synthesis of doxepin. 

The structure elucidation of salicylic acid we owe to Hermann Kolbe (1818-1884) and Victor Meyer (1848-1897). Also its industrial synthesis, from phenol and carbon dioxide, can be traced back to Kolbe, who developed this process in 1874. Previously, salicylic acid was produced by hydrolysis of its methyl ester, which in turn was obtained from wintergreen oU, a product of the steam distillation ofthe leaves ofthe American wintergreen oiteaheiry (Gaultheria procutn-bens) and the spice birch (Betula lento). 

Figure 33-4. Relationship between the growth, G (in % increase in production per year) and age, A (in years), of an industry since the introduction of the first large-scale technological process. For thermoplasts and thermosets, PL, this is the commercial phenolic resin synthesis, for glass, GL, it is the bottle production by molding process, for aluminum, Al, it is the electrolysis process, for paper, PR, it is the paper machine, and for iron, Fe, it is the use of coke. (After G. R. Snelling.)...

The following reaction is the first step in the industrial synthesis of acetone and phenol (CeHsOH). AIBN (2.2 -azobisisobutyroni-trile) initiates radical reactions by breaking down upon heating to form two isobutyronitrile radicals and nitrogen gas. Using an isobu-tyronitrile radical to initiate the reaction, write a mechanism for the following process. 

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