Aralkyl Ethers

Kim Y-H, K-H Engesser (2004) Degradation of alkyl ethers, aralkyl ethers, and dibenzyl ether by Rhodo-coccus sp. strain DEE 5151, isolated from diethyl ether-containing enrichment cultures. Appl Environ Microbiol 70 4398-4401. 

The susceptibihty of dialkyl peroxides to acids and bases depends on peroxide stmcture and the type and strength of the acid or base. In dilute aqueous sulfuric acid (<50%) di-Z fZ-butyl peroxide is resistant to reaction whereas in concentrated sulfuric acid this peroxide gradually forms polyisobutylene. In 50 wt % methanolic sulfuric acid, Z fZ-butyl methyl ether is produced in high yield (66). In acidic environments, unsymmetrical acychc alkyl aralkyl peroxides undergo carbon—oxygen fission, forming acychc alkyl hydroperoxides and aralkyl carbonium ions. The latter react with nucleophiles,... 

Boron trifluoride etherate (in HOAc, 60-80°, 15 min, high yields) also catalyzes formation of 5-diphenylmethyl and 5-triphenylmethyl thioethers from aralkyl alcohols. 

For use as a plastics material, in lacquers, or for the preparation of water-insensitive films or filaments, ethylcellulose of a relatively high degree of substitution (1.8-2.8) and the aralkyl ether, benzylcellulose (degree of substitution 1.4-2.5) have had the greatest commercial development. 

Boron trifluoride etherate, co-catalyst, 53, 30, 32 a-Bromination, selective of aralkyl ketone, 53, 111 Bromine, with 3-chlorocyclo-butanecarboxylic acid and mercuric oxide to give 1-bromo-3-chlorocyclobutane, 51, 106... 

Silyl alkyl and silyl aryl peroxides 7 are prepared by reaction of alkyl, aryl or aralkyl hydroperoxides with halosilanes (equation 12). Such reactions are carried out in an inert solvent in the presence of an acid acceptor, such as pyridine, ammonia or a tertiary amine in ether or petroleum ether (Table 3) . ... 

Rearrangement of aralkyl peroxides 8-35 Rearrangement of allylic aryl ethers (Claisen)... 

The structure (342 R,R = Me or PhCH2) of the di- -ethers of perthiocyanic acid has been confirmed by Goerdeler and his co-workers.91 These compounds, which are the products of the alkylation of perthiocyanic acid (340) or its salts,144,147 were unequivocally synthesized (t) by the interaction of 3-alkyl(or aralkyl)thio-5-chloro-l,2,4-thiadiazoles (344 R = Me or PhCH2) with the appropriate thiols (R SH)91, and (ii) by alkylation of the monoethers (345 R = Me or... 

A low purity (40-80%) divinylbenzene and chloromethylstyrene were used in the presence of a Friedel-Crafts catalyst (AICI3) for the synthesis of a polymeric phenolic antioxidant from p-cresol and l,3-bis(l-hydroxy-l-methylethyl)benzene in the presence of p-toluene sulfonic acid [115]. The obtained product was either used directly as AO for thermosetting resins or was treated consecutively with a-methylstyrene [116] or /ert-butylalcohol [117]. Other polymeric phenolic AO were obtained by reaction of phenol with p-men thane-1,8-diol, l-p-menthen-8-ol or limonene [118] or of p-cresol with 3- or 4-chloromethylstyrene in the presence of BF3-etherate or anhydrous AICI3 [119] the product thus obtained was finally aralkylated by a-methylstyrene. Thermostabilizer and/or LS for PUR was obtained, e.g. 98. 

The rearrangement products derived from aromatic and non-aromatic heterocyclic amines crystallize readily from the lower alcohols. Unlike those of many of the A-substituted glycosylamines, the crystals are not solvated. On the other hand, the ketose derivatives of aralkyl- and alkyl-amines, such as 2-phenylethylamine, ethanolamine, diethanolamine, glycine ethyl ester, and phenylalanine (see Table II), are hydrated or alcoholated, or both, and are difficult to isolate in pure crystalline form. The crystals which have been isolated were hygroscopic. Alcohols, aqueous alcohols, and water are the most commonly used solvents for crystallization. Acetone, ether, or benzene have been added to the alcoholic media in order to increase the yield of crystalline compound. The use of solvents that contain peroxides promotes decomposition of the crystals during storage. ... 

Selenium dioxide converts aryl and aralkyl allyl ethers into aldehydes and the corresponding alcohols. Allyl benzyl ether refluxed with selenium dioxide in acetic acid and dioxane for 1 h gives a 50% yield of benzyl... 

Alkyl aryl ethers are qnite stable on heating. Phenyl benzyl ether isomerizes slowly at 250 °C to afford 4-benzylphenol and its ortho-i ovasc as a minor prodnct" . The conditions of isomerizations of O-aUcylated and O-aralkylated phenols were reviewed . 

The alkyl carbon atoms of aralkyl ethers have shifts similar to those of dialkyl ethers. Note the large shift to the right of the ring ortho carbon resulting from electron delocalization as in the vinyl ethers. 

Fig. 1. Oxidation of mixtures of cumene and aralkyl hydrocarbons at 90°C, 0.02 M f-butyl perbenzoate. A, Dibenzyl ether B, indan C, diphenylmethane D, ethylbenzene E, theoretical for an inert diluent. Reprinted with permission from ref. 139. Copyright by the American Chemical Society.

The cellulose ethers are generally made by the action of alkyl or aralkyl halides on alkali cellulose. The reactions are carried out under pressure at about 100 C. The aralkyl derivative benzylcellulose, which is employed in the plastics industry, is made similarly ... 

The aralkyl celluloses, e.g., benzylcellulose and phenylethylcellulose, are made in a similar manner. Their purification may be accomplished by treating the crude alkylation mass with a selective solvent, e.g., propanol or diamyl ether, which removes organic impurities. The granular precipitate is then washed with methanol and finally with water. 

---