Aryl Methyl Ethers Research Articles

Gas chromatography of N-methyl and N-aryl carbamates by flash-heater reaction with trimethylanilinium hydroxide

A simple derivatization procedure employing trimethylanilinium hydroxide (Methelute®) is described. This method may prove useful in the analysis of certain pesticidal carbamate residues. The flash-heater reaction product derived from N-aryl carbamates was identified as the N-methyl-N-aryl carbamate. For the N-methyl carbamates, however, a methyl substitution product (aryl methyl ether) was obtained rather than the anticipated N,N-dimethyl carbamate. Using propham and carbaryl as representative compounds for the two classes of carbamates, the degree of reaction for each with Methelute was estimated to be essentially quantiative. Chromatographic response was observed to be linear with increased concentration for the synthetic standards and the flash-heater products of propham and carbaryl. At the nanogram level, flash-heater reaction improved the sensitivity of detection of propham and carbaryl by approximately 30% and 400%, respectively.

Complexation and self-association of methyl aryl ethers

Previous evidence for complexation between 1-methoxynaphthalene and n-butyllithium involving changes in the chemical shift of the ether protons has been shown to be the result of solvent effects on a self-association of the ether. The characteristics of this association have been determined. Evidence for a complex and its stoichiometry has been obtained by observation of the n-butyllithium protons.

Reactions with thioethoxide ion in dimethylformamide. I. Selective demethylation of aryl methyl ethers

Recent methods for demethylating aryl methyl ethers have been briefly reviewed, especially methods involving the use of nucleophilic reagents. Sodium thioethoxide dissolved in N,N-dimethylformamide has been developed as a powerful new reagent for demethylating aryl methyl ethers cleanly and rapidly in high yield. The reaction conditions can be controlled so that aromatic bromo substituents or isolated olefinic bonds are unaffected. Of special interest has been the selective monodemethylation of the methyl ethers of di- and tri-hydric phenols, exemplified by the isolation in high yield of orcinol monomethyl ether, p-methoxyphenol, guaiacol, and phloroglucinol dimethyl ether from the respective fully O-methylated compounds. An exception was pyrogallol trimethyl ether which afforded pyrogallol 1-monomethyl ether in high yield.

Methyl aryl ether cleavage in benzazole syntheses in polyphosphoric acid

Methyl aryl ether cleavage in benzazole syntheses in polyphosphoric acid

Demethylation of aryl methyl ethers with thioethoxide ion in dimethyl formamide

Demethylation of aryl methyl ethers with thioethoxide ion in dimethyl formamide

Demethylation of aryl methyl ethers by boron tribromide

The use of boron tribromide for effecting complete demethylation of aryl methyl ethers at, or below, room temperature is described.

The structure and chemistry of leucodrin

A novel oxidation procedure for cleaving glycol groups has been applied to leucodrin aryl methyl ether, to yield norleucodrinic acid aryl methyl ether. The study of derivatives of this product allows the derivation of the structure of leucodrin; the stability of the nor-derivative towards alkaline hydrogen peroxide is demonstrated. The cleavage of an intermediate α-keto-acid with periodic acid is substantiated.

Cleavage of some alkyl aryl ethers by triphenylsilyllithium

The reaction of triphenylsilyllithium with some methyl aryl ethers gave methyltriphenylsilane and the corresponding phenolic compound. The mild cleavage could not be extended to the ethyl or n-propyl phenyl ethers. The extreme steric sensitivity of triphenylsilyllithium is considered to be the major factor contributing to the lack of cleavage, while steric requirements of the aryl group do not appear to affect the reaction. The cleavage was not facilitated by the use of less bulky silylmetallic reagents.

The determination of phenols by chromatography and spectrophotometry of their methyl ethers: The separation and quantitative determination of methyl aryl ethers

In this, the second of a series of papers on the determination of phenols by chromatography and spectrophotometry of their methyl ethers, details are given for the quantitative methylation of phenols in microgram amounts and their separation by elution with cyclohexane. The amounts of the separated methyl aryl ethers are determined by ultra-violet spectrophotometry.

The determination of phenols by chromatography and spectrophotometry of their methyl ethers: Ultraviolet absorption spectra of methyl aryl ethers in cyclohexane

In this, the first of a series of papers on the determination of phenols, by chromatography and spectrophotometry of their methyl ethers, the determination of the ultra-violet absorption spectra in cyclohexane solution of a number of methyl ethers derived from phenols commonly present in combustion products is described.