Phenol preparation from

In the laboratory, simple phenols can be prepared from aromatic sulforae acids by melting with NaOH at high temperature (Section 16-2), Few functional groups can survive such harsh conditions, though, and the reaction is therefore limited to the preparation of alkyl-substituted phenols. Well see a better method of phenol preparation from aromatic amines in Section 24.8. 

With the exception of 4-(1,1,3,3-tetramethylbutyl)phenol prepared from diisobutylene, all the mutti-branched alkylphenols discussed consist of isomeric mixtures. In the pursuance of structure/property interests several studies have aimed to synthesise pure compounds. Thus by Wurtz-type methodology the reaction of the isomeric chloroanisoles with (i) alkyl iodides in ethereal solution in the presene of sodium and (ii) demethylation of the resultant alkylanisoles with aluminium bromide, a range of C5, Cg and Cg alkylanisoles has been synthesised (ref. 14). Numerous other methods are available for the synthesis of the isomeric n-, iso-, sec- and tert-alkylphenols some of which are referred to in Chapter 13. Reaction of a mixture of the appropriate alkyl chloride and 2-,... 

Usually prepared from the corresponding sulphonic acids by alkali fusion, methylation of phenol or from the aminotoluene by treatment with nitrous acid followed by boiling. Both o- and p-cresol are used as end components in azo dyes. 

CioHjjNOi. White crystals, m.p. 137-138°C. Prepared from phenol, via />-nitro-phenol, p-nitrophenetole and /7-phenetidine. It is used medicinally as an antipyretic analgesic similar to aspirin. It has chronic toxicity towards the kidney. 

The evidence outlined strongly suggests that nitration via nitrosation accompanies the general mechanism of nitration in these media in the reactions of very reactive compounds.i Proof that phenol, even in solutions prepared from pure nitric acid, underwent nitration by a special mechanism came from examining rates of reaction of phenol and mesi-tylene under zeroth-order conditions. The variation in the initial rates with the concentration of aromatic (fig. 5.2) shows that mesitylene (o-2-0 4 mol 1 ) reacts at the zeroth-order rate, whereas phenol is nitrated considerably faster by a process which is first order in the concentration of aromatic. It is noteworthy that in these solutions the concentration of nitrous acid was below the level of detection (< c. 5 X mol... 

Ojj 1.5323, prepared from phenol, KOH in ethanol and propargyl bromide) was added and the mixture was heated at 60°C for 15 min. It was then poured into 200 ml of ice-water and the reaction products were extracted with diethyl ether. The ethereal extracts were washed with saturated NH Cl solution, dried over magnesium sulfate and then concentrated in a water-pump vacuum. There remained 9.5 g of 3 1 mixture... 

Acetoxybenzene is prepared by the reaction of benzene with Pd(OAc)2[325,342-345], This reaction is regarded as a potentially useful method for phenol production from benzene, if carried out with only a catalytic amount of Pd(OAc)2. Extensive studies have been carried out on this reaction in order to achieve a high catalytic turnover. In addition to oxygen and Cu(II) salts, other oxidants, such as HNOi, nitrate[346,347], potassium peroxodisulfate[348], and heteropoly acids[349,3S0], are used. HNO is said to... 

The isoflavone 406 is prepared by the indirect a-phenylation of a ketone by reaction of phenylmercury(II) chloride with the enol acetate 405, prepared from 4-chromanone[371]. A simple synthesis of pterocarpin (409) has been achieved based on the oxypalladation of the oriho-mercurated phenol derivative 408 with the cyclic alkene 407[372,373]. 

Furfural has been used as a component in many resin appHcations, most of them thermosetting. A comprehensive review of the patent Hterature describing these uses is beyond the scope of this review. A few, selected recent patents and journal articles have been referenced. Resins prepared from the condensation products of furfural with urea (47), formaldehyde (48), phenols (49,50), etc, modified by appropriate binders and fillers are described in the technical Hterature for earlier appHcations, see reference 1, which contains many references in an appendix. 

Foams prepared from phenol—formaldehyde and urea—formaldehyde resins are the only commercial foams that are significantly affected by water (22). Polyurethane foams exhibit a deterioration of properties when subjected to a combination of light, moisture, and heat aging polyester-based foam shows much less hydrolytic stabUity than polyether-based foam (50,199). 

Bisa.codyl, 4,4 -(2-PyridyLmethylene)bisphenol diacetate [603-50-9] (Dulcolax) (9) is a white to off-white crystalline powder ia which particles of 50 p.m dia predominate. It is very soluble ia water, freely soluble ia chloroform and alcohol, soluble ia methanol and ben2ene, and slightly soluble ia diethyl ether. Bisacodyl may be prepared from 2-pyridine-carboxaldehyde by condensation with phenol and the aid of a dehydrant such as sulfuric acid. The resulting 4,4 -(pyridyLmethylene)diphenol is esterified by treatment with acetic anhydride and anhydrous sodium acetate. Crystallisation is from ethanol. 

Acetoiicetyliition Reactions. The best known and commercially most important reaction of diketene is the aceto acetylation of nucleophiles to give derivatives of acetoacetic acid (Fig. 2) (1,5,6). A wide variety of substances with acidic hydrogens can be acetoacetylated. This includes alcohols, amines, phenols, thiols, carboxyHc acids, amides, ureas, thioureas, urethanes, and sulfonamides. Where more than one functional group is present, ring closure often follows aceto acetylation, giving access to a variety of heterocycHc compounds. These reactions often require catalysts in the form of tertiary amines, acids, and mercury salts. Acetoacetate esters and acetoacetamides are the most important industrial intermediates prepared from diketene. 

Copolymers. The copolymer of tetrabromoBPA and BPA was one of the first commercially successhil copolymers. Low levels of the brominated comonomer lead to increased flame resistance (V-0 rating by UL 94) while having htde effect on other properties. The polycarbonate of bis(4-hydtoxyphenyl)-l,l-dichlotoethylene, prepared from chloral and phenol, followed by dehydrohalogenation, was investigated as another flame-resistant polymer which retained good impact properties. 

Halogen Displacement. Poly(phenylene oxide)s can also be prepared from 4-halo-2,6-disubstituted phenols by displacement of the halogen to form the ether linkage (48). A trace of an oxidizing agent or free radical initiates the displacement reaction. With 4-bromo-2,6-dimethylphenol, the reaction can be represented as in equation 10 ... 

A simple synthesis of tetrahydroxyben2oquinone by methoxylation—hydrolysis of chloranil has been reported (265). Similarly, tetraar5ioxyben2oquinones have been prepared from chloranil and alkali salts of phenols (266). 

AH commercial processes for the manufacture of caprolactam ate based on either toluene or benzene, each of which occurs in refinery BTX-extract streams (see BTX processing). Alkylation of benzene with propylene yields cumene (qv), which is a source of phenol and acetone ca 10% of U.S. phenol is converted to caprolactam. Purified benzene can be hydrogenated over platinum catalyst to cyclohexane nearly aH of the latter is used in the manufacture of nylon-6 and nylon-6,6 chemical intermediates. A block diagram of the five main process routes to caprolactam from basic taw materials, eg, hydrogen (which is usuaHy prepared from natural gas) and sulfur, is given in Eigute 2. 

Carbonates ate manufactured by essentially the same method as chloroformates except that more alcohol is required in addition to longer reaction times and higher temperatures. The products are neutralized, washed, and distilled. Corrosion-resistant equipment similar to that described for the manufacture of chloroformates is requited. Diaryl carbonates are prepared from phosgene and two equivalents of the sodium phenolates or with phenols and various... 

Other modifications of the polyamines include limited addition of alkylene oxide to yield the corresponding hydroxyalkyl derivatives (225) and cyanoethylation of DETA or TETA, usuaHy by reaction with acrylonitrile [107-13-1/, to give derivatives providing longer pot Hfe and better wetting of glass (226). Also included are ketimines, made by the reaction of EDA with acetone for example. These derivatives can also be hydrogenated, as in the case of the equimolar adducts of DETA and methyl isobutyl ketone [108-10-1] or methyl isoamyl ketone [110-12-3] (221 or used as is to provide moisture cure performance. Mannich bases prepared from a phenol, formaldehyde and a polyamine are also used, such as the hardener prepared from cresol, DETA, and formaldehyde (228). Other modifications of polyamines for use as epoxy hardeners include reaction with aldehydes (229), epoxidized fatty nitriles (230), aromatic monoisocyanates (231), or propylene sulfide [1072-43-1] (232). 

Lysol consists of a mixture of the three cresol isomers solubilized using a soap prepared from linseed oil and potassium hydroxide, to form a clear solution on dilution. Most vegetative pathogens, including mycobacteria, are killed in 15 minutes by 0.3—0.6% lysol. Lysol has a phenol coefficient of 2. Bacterial spores are very resistant. Lysol is also the name of a proprietary product, the formula of which has changed over the years other phenols have been substituted for the cresols. 

With Phenols. The 2-hydroxylethyl aryl ethers are prepared from the reaction of ethylene oxide with phenols at elevated temperatures and pressures (78,79). 2-Phenoxyethyl alcohol is a perfume fixative. The water-soluble alkylphenol ethers of the higher poly(ethylene glycol)s are important surface-active agents. They are made by adding ethylene oxide to the alkylphenol at ca 200°C and 200—250 kPa (>2 atm), using sodium acetate or... 

The tetrahydropyranyl ether, prepared from a phenol and dihydropyran (HCl/ EtOAc, 25°, 24 h), is cleaved by aqueous oxalic acid (MeOH, 50-90°, 1-2 h). ... 

Zn, HOAc, 25°, 1 h, 88-96% yield. Phenacyi andp-bromophenacyl ethers of phenols are stable to 1 % ethanolic alkali (reflux, 2 h), and to 5 N sulfuric acid in ethanol-water. The phenacyi ether, prepared from /3-naphthol, is cleaved in 82% yield by 5% ethanolic alkali (reflux, 2 h). 

In general, benzyl ethers are prepared from a phenol by treating an alkaline solution of the phenol with a benzyl halide. ... 

Aiyl esters, prepared from the phenol and an acid chloride or anhydride in the presence of base, are readily cleaved by saponification. In general they are more readily cleaved than the related esters of alcohols, thus allowing selective removal of phenolic esters. 9-Fluorenecarboxylates and 9-xanthenecarboxylates are also cleaved by photolysis. To permit selective removal, a number of carbonate esters have been investigated aryl benzyl carbonates can be cleaved by hydrogenolysis aryl 2,2,2-trichloroethyl carbonates, by Zn/THF-H20. 

Aryl 9-fluorenecarboxylates prepared from the phenol and the acid chloride (9-fluorenecaibonyl chloride, Pyr, C6H6, 25°, 1 h, 65% yield) can be cleaved by photolysis (hv, Et20 reflux, 4 h, 60% yield). The related aryl xanthenecarboxy-lates (i) were prepared and cleaved in the same way. ... 

The formylbenzenesulfonate prepared from a phenol (2-CHO-QH4SO2CI, Et3N) can be cleaved with NaOH (aq. acetone, rt, 5 min) in the presence of a hindered acetate. ... 

Dimethoxybenzyl esters prepared from the acid chloride and the benzyl alcohol are readily cleaved oxidatively by DDQ (CH2CI2, H2O, rt, 18 h, 90-95% yield). A 4-methoxybenzyl ester was found not to be cleaved by DDQ. The authors have also explored the oxidative cleavage (ceric ammonium nitrate, CH3CN, H2O, 0°, 4 h, 65-97% yield) of a variety of 4-hydroxy- and 4-amino-substituted phenolic esters. ... 

Sulfonamides (R2NSO2R ) are prepared from an amine and sulfonyl chloride in the presence of pyridine or aqueous base. The sulfonamide is one of the most stable nitrogen protective groups. Arylsulfonamides are stable to alkaline hydrolysis, and to catalytic reduction they are cleaved by Na/NH3, Na/butanol, sodium naphthalenide, or sodium anthracenide, and by refluxing in acid (48% HBr/cat. phenol). Sulfonamides of less basic amines such as pyrroles and indoles are much easier to cleave than are those of the more basic alkyl amines. In fact, sulfonamides of the less basic amines (pyrroles, indoles, and imidazoles) can be cleaved by basic hydrolysis, which is almost impossible for the alkyl amines. Because of the inherent differences between the aromatic — NH group and simple aliphatic amines, the protection of these compounds (pyrroles, indoles, and imidazoles) will be described in a separate section. One appealing proj>erty of sulfonamides is that the derivatives are more crystalline than amides or carbamates. 

Polymers have been prepared from nuclear substituted di-(4-hydroxyphenyl)-alkanes, of which the halogenated materials have been of particular interest. The symmetrical tetrachlorobis-phenol A yields a polymer with a glass transition temperature of 180°C and melting range of 250-260°C but soluble in a variety of solvents. 

A range of polysulphones has been prepared with a variety of bis-phenols other than bis-phenol A. As might be expected from the discussion in Chapter 4 and from experience with the range of polycarbonates (Chapter 20), replacement of the isopropylidene link with a methylene, sulphide or oxygen link depresses the Tg whilst —C(CgH5)2— and sulphone links raise it. The bis-phenol derived from norcamphor leads to a polysulphone with a Tg of 250°C (195°C for a Udel-type polymer). 

In lithium-ion battery applications, it is important to reduce the cost of electrode materials as much as possible. In this section, we will discuss hard carbons with high capacity for lithium, prepared from phenolic resins. It is also our goal, to collect further evidence supporting the model in Fig. 24. 

Fig. 32. Reversible capacity of microporous carbon prepared from phenolic resins heated between 940 to 1 I00°C plotted as a function of the X-ray ratio R. R is a parameter which is empirically correlated to the fraction of single-layer graphene sheets in the samples.

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