Phenyl methyl ether, reaction

Repeat this analysis for the reaction of phenyl methyl ether with HI leading to phenol and methyl iodide or methanol and phenyl iodide and involving protonated phenyl methyl ether as an intermediate. (Note In this case, the appropriate empty molecular orbital is LUMO+2 the LUMO is concentrated primarily on the CO bond.) Which reaction, with ethyl propyl ether or phenyl methyl ether, appears to be more likely to give selective ether cleavage ... 

PHENYL METHYL ETHER (100-66-3) Forms explosive mixture with air (flash point 125°F/51°C oc). Able to form unstable peroxides. Violent reaction with oxidizers, strong acids. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

There is also a single case reported in which a phenyl methyl ether was prepared from the corresponding aryl chloride. Potassium methoxide, activated by dicyclo-hexyl-18-crown-6 displaces a chloride ion from 1,2-dichlorobenzene to give 2-chloro-anisole in fair yield. None of the 3-isomer is isolated, indicating that the reaction is a nucleophilic substitution rather than a benzyne reaction [22]. 

The occurrence of arenediazo alkyl and aryl ethers as intermediates has been discussed since 1870, when Kekule and Hidegh postulated that in the azo coupling reaction of benzenediazonium salts with phenol, 4-phenylazophenol is formed via the diazo phenyl ether. The analogous problem for diazo methyl ethers was first discussed by von Euler (1903). 

In the course of this study, the authors determined /Lvalues for dibenzyl, methyl phenyl, methyl p-nitrophenyl, di-p-tolyl, di-isopropyl and tetramethylene sulphoxides and for diethyl, dipropyl and dibutyl sulphites. The /Lscales are applied to the various reactions or the spectral measurements. The /Lscales have been divided into either family-dependent (FD) types, which means two or more compounds can share the same /Lscale, family-independent (FI) types. Consequently, a variety of /Lscales are now available for various families of the bases, including 29 aldehydes and ketones, 17 carboxylic amides and ureas, 14 carboxylic acids esters, 4 acyl halides, 5 nitriles, 10 ethers, 16 phosphine oxides, 12 sulphinyl compounds, 15 pyridines and pyrimidines, 16 sp3 hybridized amines and 10 alcohols. The enthalpies of formation of the hydrogen bond of 4-fluorophenol with both sulphoxides and phosphine oxides and related derivatives fit the empirical equation 18, where the standard deviation is y = 0.983. Several averaged scales are shown in Table 1588. 

Alkenes are scavengers that are able to differentiate between carbenes (cycloaddition) and carbocations (electrophilic addition). The reactions of phenyl-carbene (117) with equimolar mixtures of methanol and alkenes afforded phenylcyclopropanes (120) and benzyl methyl ether (121) as the major products (Scheme 24).51 Electrophilic addition of the benzyl cation (118) to alkenes, leading to 122 and 123 by way of 119, was a minor route (ca. 6%). Isobutene and enol ethers gave similar results. The overall contribution of 118 must be more than 6% as (part of) the ether 121 also originates from 118. Alcohols and enol ethers react with diarylcarbenium ions at about the same rates (ca. 109 M-1 s-1), somewhat faster than alkenes (ca. 108 M-1 s-1).52 By extrapolation, diffusion-controlled rates and indiscriminate reactions are expected for the free (solvated) benzyl cation (118). In support of this notion, the product distributions in Scheme 24 only respond slightly to the nature of the n bond (alkene vs. enol ether). The formation of free benzyl cations from phenylcarbene and methanol is thus estimated to be in the range of 10-15%. However, the major route to the benzyl ether 121, whether by ion-pair collapse or by way of an ylide, cannot be identified. 

The difference in reactivity between isoprenol and isoprenyloxide, methal-lyl methyl ether and methallyloxide were investigated in the reaction with (phenylthio)carbene generated under phase-transfer conditions. With isoprenol, (phenylthio)methyl ether (41%) was the major product, whereas with methyl ether cyclopropanation (36%) was the sole reaction.1519 With alkoxides, in contrast, the major product was the C-H insertion product (45%) and (phenyl-... 

Homoallyl ethers or sulfides.1 gem-Methoxy(phenylthio)alkanes (2), prepared by reaction of 1 with alkyl halides, react with allyltributyltin compounds in the presence of a Lewis acid to form either homoallyl methyl ethers or homoallyl phenyl sulfides. Use of BF3 etherate results in selective cleavage of the phenylthio group to provide homoallyl ethers, whereas TiCl effects cleavage of the methoxy group with formation of homoallyl sulfides. 

Some obscurities. Each of the reactions mentioned has been identified in at least one system, but there are very many obscurities to be cleared up. For example, transfer by methyl vinyl ether, phenyl vinyl ether, vinyl acetate and some of the corresponding polymers in the polymerization of styrene by stannic chloride has been studied, but the mechanism is not at all clear [124]. 

This is the third report on attempts to measure the propagation rate constant, kp+, for the cationic polymerisation of various monomers in nitrobenzene by reaction calorimetry. The first two were concerned with acenaphthylene (ACN) [1, 2] and styrene [2]. The present work is concerned with attempts to extend the method to more rapidly polymerising monomers. With these we were working at the limits of the calorimetric technique [3] and therefore consistent kinetic results could be obtained only for indene and for phenyl vinyl ether (PhViE), the slowest of the vinyl ethers 2-chloroethyl vinyl ether (CEViE) proved to be so reactive that only a rough estimate of kp+ could be obtained. Most of our results were obtained with 4-chlorobenzoyl hexafluoroantimonate (1), and some with tris-(4-chlorophenyl)methyl hexafluorophosphate (2). A general discussion of the significance of all the kp values obtained in this work is presented. 

Column III shows the effect of ultrasound upon the product ratio with methanol as solvent. As can be seen there is now 53 % bibenzyl, 32 % of methyl ether and 6% of methyl ester (with a total of 5 % of other products) suggesting a slight shift towards the two-electron products, but with an overall diminuition of solvent discharge (approx. 6% ester) and side-reactions (approx. 6%). This result confirms the fact the phenyl acetate electrooxidation favours the one-electron route (to bibenzyl) in a wide range of conditions [61], and is much less sensitive to mechanistic switches by manipulation of parameters (e. g. ultrasound) than is cyclohexane carboxylate electrooxidation [54]. 

Oxidation of alkyl phenyl telluride with excess meto-chloroperbenzoic acid (MCPBA) (3-5 equiv) in methanol affords the replacement of the phenyltellurium moiety by a methoxy group, giving the corresponding methyl ethers - (method A). This reaction. 

Among the various polar solvents tested, acetonitrile, dichloromethane, and THF afforded good yields of the expected product, although with moderate diastereo-selectivity (Table 16, entries 1-3). The most suitable solvent was found to be diethyl ether. 5-[Hydroxy(phenyl)methyl furan-2(5//)-one 28a was obtained with the best yield and diastereoselectivity (Table 16, entry 4). With further optimization of the reaction conditions, we found that a lower catalyst loading (0.5 mol%) did not allow the reaction to proceed (Table 16, compare entries 5 and 4), although a higher catalyst loading (5 mol%) afforded the product with close diastereoselectivity but decreased yield (Table 16, compare entries 6 and 4). 

Holm determined the enthalpies of formation of a collection of hydrocarbyhnagnesium bromides by reaction calorimetry with HBr in diethyl ether . He also determined the enthalpies of formation in ethereal solution of the magnesium bromide salts of 20 Bronsted acids, HB, by measuring the enthalpies of reaction of the acid with pentylmag-nesium bromide. For those species that were reported in both studies (hydrocarbyl = phenylethynyl, phenyl, methyl, cyclopropyl, cyclopentyl, cyclohexyl), the enthalpies of formation were identical. The values are listed in Tables 3 and 4. 

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