Alkylation of phenolates

Me3CCH2CMe2C H40H. M.p. 8l-83"C, b.p. 286-288°C. Made by alkylation of phenol. Forms oil-soluble resins with methanal (salts used as oil additives) and surfactants (with ethylene oxide). 

Sulfonated styrene—divinylbensene cross-linked polymers have been appHed in many of the previously mentioned reactions and also in the acylation of thiophene with acetic anhydride and acetyl chloride (209). Resins of this type (Dowex 50, Amherljte IR-112, and Permutit Q) are particularly effective catalysts in the alkylation of phenols with olefins (such as propylene, isobutylene, diisobutylene), alkyl haUdes, and alcohols (210) (see Ion exchange). Superacids. 

Additioaal uses for higher olefias iaclude the productioa of epoxides for subsequeat coaversioa iato surface-active ageats, alkylatioa of benzene to produce drag-flow reducers, alkylation of phenol to produce antioxidants, oligomeriza tion to produce synthetic waxes (qv), and the production of linear mercaptans for use in agricultural chemicals and polymer stabilizers. Aluminum alkyls can be produced from a-olefias either by direct hydroalumination or by transalkylation. In addition, a number of heavy olefin streams and olefin or paraffin streams have been sulfated or sulfonated and used in the leather (qv) iadustry. 

Alkylphenols containing 3—12-carbon alkyl groups are produced from the corresponding alkenes under acid catalysis. Alkylphenols containing the methyl group were traditionally extracted from coal tar. Today they are produced by the alkylation of phenol with methanol. 

The alkylation of phenol with an alkene using either acid or aluminum catalysis probably accounts for 95% of the commercially produced alkylphenols with alkyl groups of three carbons or larger. The alkenes are commercially available and environmentally kind. They do not produce by-products as do alkylations which use alcohols or alkyl haUdes. Together with an acid catalyst and the appropriate amount of phenol, mono-, di-, and trialkylphenols can be produced. 

The cmde product formed from the alkylation of phenol with isoamylene contains principally 2-/ r2 -amylphenol, 4-/ r2 -amylphenol, and 2,4-di-/ r2 -amylphenol. 4-/ r2 Amylphenol is purified to its typical assay of 99+% by fractional distillation. 4-/ r2 -Amylphenol [80-46-6] is commercially available as a soHd, flaked material packaged ia paper or plastic bags (25 kg net weight) or as a molten material ia tank wagon or railcar quantities. 

Gumylphenol. -Cumylphenol (PGP) or 4-(1-methyl-l-phenylethyl)phenol is produced by the alkylation of phenol with a-methylstyrene under acid catalysis. a-Methylstyrene is a by-product from the production of phenol via the cumene oxidation process. The principal by-products from the production of 4-cumylphenol result from the dimerization and intramolecular alkylation of a-methylstyrene to yield substituted indanes. 4-Cumylphenol [599-64-4] is purified by either fractional distillation or crystallization from a suitable solvent. Purification by crystallization results in the easy separation of the substituted indanes from the product and yields a soHd material which is packaged in plastic or paper bags (20 kg net weight). Purification of 4-cumylphenol by fractional distillation yields a product which is almost totally free of any dicumylphenol. The molten product resulting from purification by distillation can be flaked to yield a soHd form however, the soHd form of 4-cumylphenol sinters severely over time. PGP is best stored and transported as a molten material. 

Methylphenol. This phenol, commonly known as o-cresol, is produced synthetically by the gas phase alkylation of phenol with methanol using modified alumina catalysis or it may be recovered from naturally occurring petroleum streams and coal tars. Most is produced synthetically. Reaction of phenol with methanol using modified zeoHte catalysts is a concerted dehydration of the methanol and alkylation of the aromatic ring. 2-Methylphenol [95-48-7] is available in 55-gal dmms (208-L) and in bulk quantities in tank wagons and railcars. 

Diall lated Phenols. 2,4-Di-tert-amjlphenol (2,4-DTAP) or 2,4-bis(l,l-dimethylpropyl)phenol is produced by the alkylation of phenol with isoamylene under acid catalysis in a mole ratio of 2 1 (isoamylene to phenol). The cmde alkylation product contains 4-/ f2 -amylphenol,... 

Di-sec-butylphenol (DSBPJ is produced by the alkylation of phenol with 1-butene or 2-butene under acidic or aluminum catalysis. The production of di-j -butylphenol under acid catalysis gives a 2 to 1 mixture of 2,4-di-j -butylphenol and 2,6-di-j -butylphenol [2,4-bis(l-methylpropyl)phenol and... 

Toluenesulfonic Acid. Toluene reacts readily with fuming sulfuric acid to yield toluene—sulfonic acid. By proper control of conditions, /)i7n7-toluenesulfonic acid is obtained. The primary use is for conversion, by fusion with NaOH, to i ra-cresol. The resulting high purity i7n -cresol is then alkylated with isobutylene to produce 2 (i-dii-tert-huty -para-cmso (BHT), which is used as an antioxidant in foods, gasoline, and mbber. Mixed cresols can be obtained by alkylation of phenol and by isolation from certain petroleum and coal-tar process streams. 

Di- and Triisobutylcncs. Diisobutylene [18923-87-0] and tnisobutylenes are prepared by heating the sulfuric acid extract of isobutylene from a separation process to about 90°C. A 90% yield containing 80% dimers and 20% trimers results. Use centers on the dimer, CgH, a mixture of 2,4,4-trimethylpentene-1 and -2. Most of the dimer-trimer mixture is added to the gasoline pool as an octane improver. The balance is used for alkylation of phenols to yield octylphenol, which in turn is ethoxylated or condensed with formaldehyde. The water-soluble ethoxylated phenols are used as surface-active agents in textiles, paints, caulks, and sealants (see Alkylphenols). 

Cationic alkylation of phenol takes place by the action of perfluoroalkyl-phenyliodonium trifluoromethanesullonates [161] (equation 138)... 

Another example of preferential solvation is provided by the inhibition by dioxane of the aiyl alkylation of phenol by r-butyl chloride. ... 

Alkylation of phenol 53 with 1,6-dibromohexane gives haloether... 

Starting material for the first of these agents can in principle be obtained by alkylation of phenol with benzyl chloride 89. Cyclization of the product (90) under Friedel-Crafts conditions leads directly to isoxepac (91). ... 

The kinetics of alkylation by triphenylmethyl compounds have been studied. Hart and Cassis353 found that the alkylation of phenol and o-cresol by triphenylmethyl chloride in o-dichlorobenzene gave non-linear kinetic plots which were, however, rendered linear by presaturation of the reaction mixture with hydrogen chloride, precise third-order kinetics, equation (182)... 

The SR 33557 is obtained by alkylation of phenol 2 with the appropriate chloro-alkylamine. 

Owing to its excellent thermal and mechanical stability and its rich chemistry, alumina is the most widely used support in catalysis. Although aluminium oxide exists in various structures, only three phases are of interest, namely the nonporous, crys-tallographically ordered a-Al203, and the porous amorphous t]- and y-Al203. The latter is also used as a catalyst by itself, for example in the production of elemental sulfur from H2S (the Claus process), the alkylation of phenol or the dehydration of formic acid. 

O-Alkylation of phenols Phenol/cresols/catechols, alkyl halides/dimethyl sulphate/diethyl sulphate... 

The tuning of solubility with a relatively small jump or fall in pressure can possibly bestow many benefits with respect to rates, yields, and selectivity. Reaction parameters can be changed over a wide range. Replacement of solvents with high boiling points by supercritical (SC) fluids offers distinct advantages with respect to removal of the solvent. SC fluids like CO2 are cheap and environmentally friendly the critical temperature of CO2 is 31 C and the critical pressure 73.8 atm (Poliakoff and Howdle, 1995). Eckert and Chandler (1998) have given many examples of the use of SC fluids. Alkylation of phenol with tcrt-butanol in near critical water at 275 °C allows 2- erf-butyl phenol to be formed (a major product when the reaction is kinetically controlled 4-rert-butyl phenol is the major product, when the reaction is... 

Interposition of an oxygen atom between the aromatic ring and the imidazoline-bearing side chain leads to a compound reported to show antidepressant activity. Its preparation begins with alkylation of phenol 125 with chloroacetonitrile to afford intermediate 126. Condensation of that nitrile with the... 

The literature on basic- and acid-catalyzed alkylation of phenol and of its derivatives is wide [1,2], since this class of reactions finds industrial application for the synthesis of several intermediates 2-methylphenol as a monomer for the synthesis of epoxy cresol novolac resin 2,5-dimethylphenol as an intermediate for the synthesis of antiseptics, dyes and antioxidants 2,6-dimethylphenol used for the manufacture of polyphenylenoxide resins, and 2,3,6-trimethylphenol as a starting material for the synthesis of vitamin E. The nature of the products obtained in phenol methylation is affected by the surface characteristics of the catalyst, since catalysts having acid features address the electrophilic substitution in the ortho and para positions with respect to the hydroxy group (steric effects in confined environments may however affect the ortho/para-C-alkylation ratio), while with basic catalysts the ortho positions become the... 

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