Phenols condensation with acetone

A variant (BP scheme) consists in first separating the crude phenol from the acetone/ hydrocarbon combination, which is then treated separately. The phenol thus produced has a purity of about 99.8 per cent weight The 2000 ppm of ketone impurities which it contains make it often unsuitable for use in sulfooation,. chlorination and condensation with acetone (bispbenol), in line with the increasingly stringent quality requirements of commercial products. 

Bisphenol A. One mole of acetone condenses with two moles of phenol to form bisphenol A [80-05-07] which is used mainly in the production of polycarbonate and epoxy resins. Polycarbonates (qv) are high strength plastics used widely in automotive appHcations and appHances, multilayer containers, and housing appHcations. Epoxy resins (qv) are used in fiber-reinforced larninates, for encapsulating electronic components, and in advanced composites for aircraft—aerospace and automotive appHcations. Bisphenol A is also used for the production of corrosion- and chemical-resistant polyester resins, polysulfone resins, polyetherimide resins, and polyarylate resins. 

Bis-phenol A may be produced by the condensation of phenol with acetone under acidic conditions (Figure 20.2). 

We have found several examples in which adjacent cationic charge centers are shown to activate carboxonium electrophiles. A convenient method for studying this activation is through the use of the hydroxyalkylation reaction, a commercially important, acid-catalyzed condensation of aldehydes and ketones with arenes.10 It is used for example in the synthesis of bis-phenol A from acetone and phenol (eq 6). While protonated acetone is able to react with activated arenes like phenol, it is not capable of reacting with less nucleophilic... 

Acid Catalyzed. Although ketonic carbonyl groups are less reactive than aldehydic carbonyls in the presence of basic catalysts, this is not the case with acid catalysts. Thus acetone undergoes aldol addition in the presence of sulfuric acid to give mesityl oxide, which then condenses with a third molecule of acetone to give a mixture ofphorone (2,6-dimethyl-2,6-heptadien-4-one) and mesitylene (1,3,5-trimethylbenzene). Ketones also condense with activated aromatic products in the presence of sulfuric acid to give coupled aromatic products. For example, acetone and phenol condense to bisphenol A (4,4 -isopropylidenediphenol), which is used in the manufacture of epoxy resins (qv) and polycarbonates (qv). 

Other alkylation reactions are observed in the condensation of cyclo-propanium ions (generated in situ) with ketones 89.92)> enamines6, nitroalkanes 93>, dimethylmalonate 92>, and phenol. 92> Thus, 7-hydroxy-7-pyrrolidinobicyclo[4.1.0]heptane (56) as well as the 7,7-dipyrrolidino derivative (54) react with acetone to give the amino ketone 113. 89> This reaction may be pictured as an addition of the enol form of the ketone to the reactive iminium salt formed from the carbinol amine. In like manner, phenol undergoes ortho substitution with the carbinol amine 114 formed from cyclopropanone and dimethyl amine. 

Besides, furfural polymerizes in the presence of an acid catalyst with phenol, urea, and acetone. In this regard, the phenol-furfural and urea-furfural resins are important [221-223], Furfural reacts usually as does all a-substituted aldehydes in this regard, with phenol it condenses in the presence of either alkali or acid to form synthetic resins in a reaction that is very similar to that of phenol with formaldehyde or acetaldehyde [223],... 

Aromatic amines, such as phenyl- -naphthylamine or condensation products of diphenylamine with acetone condensates, are excellent antioxidants and antiozonants but cause color development. From the sterically hindered phenols, monocyclic phenols, such as 2,6-di-teit-butyl-p-cresol, are less effective antioxidants but remain white and nontoxic during aging. They are, however, volatile and provide poor protection at elevated processing temperatures. Polycyclic phenols, such as 2,2 -methylene-bis (4-methyl-6-teit-butylphenol), are relatively nonvolatile, but become discolored by oxidation to a conjugated system. O Shea... 

Bisphenol A is made on a large scale by a condensation of phenol with acetone. Suggest an appropriate catalyst, and propose a mechanism for this reaction. Hint This is a condensation because three molecules are joined with loss of water. The mechanism belongs to another class of reactions, though.)... 

One of the earliest commercial plastics was Bakelite , formed by the reaction of phenol with a little more than one equivalent of formaldehyde under acidic or basic conditions. Baeyer first discovered this reaction in 1872, and practical methods for casting and molding Bakelite were developed around 1909. Phenol-formaldehyde plastics and resins (also called phenolics) are highly cross-linked because each phenol ring has three sites (two ortho and one para) that can be linked by condensation with formaldehyde. Suggest a general structure for a phenol-formaldehyde resin, and propose a mechanism for its formation under acidic conditions. (Hint Condensation of phenol with formaldehyde resembles the condensation of phenol with acetone, used in Problem 26-17, to make bisphenol A.)... 

Besides alkoxides, acetylacetonates are also used as the starting materials for the synthesis of oxides. Titania (anatase) is obtained by decomposition of titanium oxyacetylacetonate (TiO(acac)2) in toluene at 300°C. Similarly solvothermal treatment of Fe(lll) acetylacetonate in toluene yields microcrystalline magnetite. One of the drawbacks of the use of acetylacetonate may be formation of various high boiling point organic by-products via aldol-type condensation of the acetylacetone. Actually more than 50 compounds are detected by gas chromatography-mass spectrometry (GC-MS) analysis of the supernatant of the reaction, some of which are phenolic compounds and are hardly removed from the oxide particles by washing with acetone. ... 

Holmstedt et al. found that terminal primary amines condense readily with acetone, therefore a phenolic amine (serotonine) gives the corresponding trimethyl silyl ether-acetone condensation product when silylation is carried out in acetone solution. Primary amines may be entirely lost on a NGS column, but the acetone condensation products have a normal behaviour under these conditions. The relative retention times for indole bases related to tryptamine are summarized in Table 17.1. 

The condensation of phenol with acetone was also extensively studied and a catalyst prepared that gives high conversion and good selectivity to the desired product p-,p-bisphenol-A. 

Epoxy resins first developed commercially and still completely dominating the worldwide markets are those based on 2,2-bis(4 -hydroxyphenyl) propane, more commonly known as bisphenol A (as it is produced by condensation of phenol with acetone) and l-chloro-2,3-epoxy-propane, also known as epichlorohydrin. It can be seen from the general formula of these resins that the molecular species concerned is a linear polyether with terminal glycidyl ether group... 

Pinosylvin (3,5-stilbenediol) ( )-form needles, insoluble in water, soluble in acetone. )- and (Z)-isomers occur together with the corresponding mono- and dimethyl ethers in pines, firs, and conifers. Pinosylvin has antifungal and antibacterial activities and protects the wood against rot, as a disinfectant it is 30-times stronger than phenol and is highly toxic for fish. As a result of condensation with lignin, pinosylvin prevents sulfite dissolution of wood. Pinosylvin monomethyl ether acts as an antifeedant for certain rabbit species. ... 

Bisphenol A is produced by the condensation reaction of excess phenol with acetone in the presence of an acidic catalyst. Sulfur compounds that may be used as a cocatalyst include alkyl mercaptans, such as methyl mercaptan, ethyl mercaptan and thioglycol acid. Recently, a catalyst composed of an acid-type ion exchange resin, which is modified in part with a sulfur-... 

Phenol is mainly derived from benzene, but can also be obtained from propylene. It serves as the basis for several important monomers, in addition to its direct use as a reactive monomer via condensation with formaldehyde. This first man-made polymer, phenol-formaldehyde, appeared in 1901 and bears the trademark Bakelite , after its inventor Bakeland. By reacting phenol with acetone, bis-phenol A is obtained. This serves as the basis for the manufacture of epoxy and polycarbonate. 

Bisphenol A and F n. Dihydroxydiphenyldi-methylmethane, mol wt 224.1. Insoluble in water. Used in the manufacture of phenolic and epoxy resins. Condensation product formed by reaction of two (bis) molecules of phenol with acetone. This polyhydric phenol is a standard resin intermediate, along with epichlorohydrin, in the production of epoxy resins (See image). 

Offering for example enhanced heat and chemical resistance over even the best tetraphthalic polyester, there is close chemical relationship between the other two and the bisphenol-A starting point, a condensation product of phenol with acetone under acidic conditions. Then come those epoxides which, as a product of a further reaction between bisphenol and epichlorohydrin, are applicable to composites. In turn the vinyl esters can be considered as an epoxy resin backbone with terminal acrylic ester groups, dissolved in or diluted by -similar to unsaturated polyester - a monomer like styrene, which can itself be polymerised. All are chemically cured or promoted, with or without the addition of heat, although the epoxides are more selective to the use of amines for this purpose, than the other two where the peroxides are the more common. 

Bisphenol-A (BPA) is an important raw material for the synthesis of polycarbonates, epoxy resins and other polymers as well as polymer additives. It is conventionally produced by acid-catalysed condensation of phenol with acetone. Application of various catalysts for the BPA synthesis is discussed with particular attention to the substrates conversion and the reaction selectivity. Recent developments in the BPA production and its applications are presented. Moreover, potential toxicological and endocrine disrupting properties of BPA are considered with the emphasis on human exposure, general toxicology, and biological effects. 

Bisphenol-A is prepared by condensation of acetone (as denoted by the suffix A in the name) with two equivalents of phenol, catalyzed by an acid, such as sulphuric acid or hydrochloric acid (Figure 7.2). 

Figure 7.9 The side reactions occurring during the condensation of phenol with acetone. The formation of o.p-BPA isomers (1), mesityl oxide (2), the chromans (3 and 4). trisphenol (5). l,1.3-trimethyl-5-indanol (6), alkylated phenols (7) and 2,2.4-trimethylchromen (8) [40,41,43,45).

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