Ether phenol

The Hoesch Reaction is employed for the introduction of the - COR group into the aromatic ring of phenol or a phenolic ether, and usually proceeds particularly readily with polyhydric phenols. If an ethereal solution of resorcinol (I)... 

The Gattermann-Koch formylatioii was found unsuited to the preparation of aldehydes from phenols and phenol ethers such aldehydes may be obtained by Gatteimann s aldehyde reaction. 

By interaction of hydrogen cyanide and hydrogen chloride with an anxnatic compound (hydrocarbon, phenol or phenol ether) in the presence of aluminium chloride (or zinc chloride). This is known as the Gattermann... 

By the condensation of a nitrile with a phenol or phenol ether in the presence of zinc chloride and hydrogen chloride a hydroxyaryl- or alkoxyaryl-ketone is produced. The procedure is termed the Hoesch reaction and is clearly an extension of the Gattermann aldehyde reaction (Section IV,121). The reaction gives the best results with polyhydric phenols and their ethers with simple monohydric phenols the imino ester hydrochloride is frequently the sole product for example ... 

Naphthalene is very slightly soluble in water but is appreciably soluble in many organic solvents, eg, 1,2,3,4-tetrahydronaphthalene, phenols, ethers, carbon disulfide, chloroform, ben2ene, coal-tar naphtha, carbon tetrachloride, acetone, and decahydronaphthalene. Selected solubiUty data are presented in Table 4. 

Phenols and phenol ethers readily undergo mono-, di-, or trihromination in inert solvents depending on the amount of bromine used. In water the main product is the 2,4,6-tribromophenol [118-79-6] C H Br O (23). In water or acetic acid anilines also give the tribrorninated product (25). 

Like other alkaloids of this group, quinine forms molecular compounds with a variety of organic substances. With benzene and toluene it produces compounds of the formulae B. CgHg and B. C,Hg respectively, with phenol it gives the crystalline product B. CgHjOH, and similar combinations with polyhydric phenols, ethers, aldehydes and ketones are known. One of the most characteristic of these substances is cupreine-quinine, a combination of the two alkaloids, obtainable from cuprea bark, and at first regarded as a new alkaloid, and named homoquinine. ... 

A carbonyl group cannot be protected as its ethylene ketal during the Birch reduction of an aromatic phenolic ether if one desires to regenerate the ketone and to retain the 1,4-dihydroaromatic system, since an enol ether is hydrolyzed by acid more rapidly than is an ethylene ketal. 1,4-Dihydro-estrone 3-methyl ether is usually prepared by the Birch reduction of estradiol 3-methyl ether followed by Oppenauer oxidation to reform the C-17 carbonyl function. However, the C-17 carbonyl group may be protected as its diethyl ketal and, following a Birch reduction of the A-ring, this ketal function may be hydrolyzed in preference to the 3-enol ether, provided carefully controlled conditions are employed. Conditions for such a selective hydrolysis are illustrated in Procedure 4. 

Oxidative reactions frequently represent a convenient preparative route to synthetic intermediates and end products This chapter includes oxidations of alkanes and cycloalkanes, alkenes and cycloalkenes, dienes, aromatic fluorocarbons, alcohols, phenols, ethers, aldehydes and ketones, carboxylic acids, nitrogen compounds, and organophosphorus, -sulfur, -selenium, -iodine, and -boron compounds... 

The quantitative deprotection of phenol ethers can be achieved by the action of a catalytic amount of triflic acid in trifluoroethanol at -5 °C [86],... 

Hychoxyaldehydes hate been obttiined indirectly by the use of the crystalline compound HCl.HCN (which hychochloiic acid forms with hydrocyanic acid) acting upon a phenol ether,... 

Plicnoh.— If it is a free phenol, ether will extiact it from its ac ueous solution. If it is present in alkaline solution, the solution should first be saturated with cat bon dioxide. (n.B.—The alkaline solutions of catecliol, quinol and pyrogallol daiken rapidly m the air.) The following tests should then be applied. 

Liquids.—It may be a hydrocarbon (paraffin,olefine,aromatic) Jiiyher alcohol e.g. amyl alcohol), aldehyde [eg., benzaldehyde) ketone [eg., acetophenone) acid [e.g., valeric acid), ether, cdei, phenol [e.g., zveewtiCxaX) phenol ether [e.g, anisole). 

Phenols and phenol ethers can be acylated with y- or S-amino acids in the presence of polyphosphoric acid to form 2-aryl-2d -pyrrolines (11, = 1) or 2-aryl-/l -piperideines (11, n = 2), respectively (13). 

The applicability of the Gattermann synthesis is limited to electron-rich aromatic substrates, such as phenols and phenolic ethers. The introduction of the formyl group occurs preferentially para to the activating substituent (compare Friedel-Crafts acylation). If the /jara-position is already substituted, then the ort/zo-derivative will be formed. 

An analogous reaction is the Houben-Hoesch reaction,(sometimes called the Hoesch reaction) using nitriles 7 to give aryl ketones 8. This reaction also is catalyzed by Lewis acids often zinc chloride or aluminum chloride is used. The Houben-Hoesch reaction is limited to phenols—e.g. resorcinol 6—phenolic ethers and certain electron-rich aromatic heterocycles ... 

The guanidine function, when attached to an appropriate lipophilic function, often yields compounds that exhibit antihypertensive activity by means of their peripheral sympathetic blocking effects. Attachment of an aromatic ring via a phenolic ether seems to fulfill these structural requirements. Alkylation of 2,6-dichlorophenol with bromochloroethane leads to the intermediate, 58. Alkylation of hydrazine with that halide gives 59. Reaction of the hydrazine with S-methylthiourea affords the guanidine, guanoclor (60). ... 

Reaction of the potassium salt of salicylaldehyde with chlo-roacetone affords first the corresponding phenolic ether aldol cyclization of the aldehyde with the ketonic side chain affords the benzofuran (1). Reduction of the carbonyl group by means of the Wolf-Kischner reaction affords 2-ethyl-benzofuran. Friedel-Crafts acylation with anisoyl chloride proceeds on the remaining unsubstituted position on the furan ring (2). The methyl ether is then cleaved by means of pyridine hydrochloride (3). lodina-tion of the phenol is accomplished by means of an alkaline solution of iodine and potassium iodide. There is thus obtained benziodarone (4)... 

Semmler has detected a small qnaotitv of a sesquiterpene alcohol, and a phenol ether to which he assigned the name elemicin. This body h 3 a specific grariiy 1-063 at 30, refractive index 1 3365, aud boils at 144 to 147 - at lO mm. 

Para substituted phenol ethers Ring substituted dihydroxj benzenes Cyclohexane alcohols Menthenols. ... 

This phenolic ether, CgH3(OH)(OCH3)2, has been identified in the essential oil of an Algerian plant, whose botanical source is not identified. It is a crystalline body melting at 51°, and yields a benzoyl derivative melting at 107° to 108°. 

On oxidation it yields veratric acid melting at 179° to 180°, and by the action of bromine on the phenol-ether dissolved in absolute ether, a dibromide is obtained, which melts at 101° to 102°. It has the constitution—... 

This phenol ether has been isolated from French oil of parsley. It is a crystalline compound of the formula Cj3Hjg04, which can be separated by freezing the oil and drying the crystals on porous plates for twenty-four bouts, and recrystallising the product several times from alcohol. Its constitution is as follows —... 

On oxidation with permanganate of potassium, this phenol ether yields tetramethoxy benzoic acid, C H(OCH3)4COOH, melting at 87°. 

Phenolat, n. phenoxide, phenolate. Phenol-ather, m. phenol ether, -carbonsaure, /. phenolcarboxylic acid, -gruppe, /, phenol group,... 

Most of the chemistry of PA is determined by its acidic nature. It is a strong acid whose ionization constant of 1.6 x 10"1 (Ref 31) makes it comparable in acid strength to pyrophosphoric acid and trichloroacetic acid. PA readily forms salts with bases and esters with alcohols. The salts are known as Picrates. Many of them are expl and will be described in a separate article in this Vol. The esters are phenol ethers, eg, Trinitro-anisolc (see Vol t, A450-L)... 

Phenol ethers show some, admittedly low, reactivity towards diazonium ions and also undissociated phenols (see Sec. 12.7). An instructive example of the reactivity of phenol ethers was reported by Ronaldson (1981). He found that 1,2-dimethoxy-benzene (veratrole) does not react with the 4-nitrobenzenediazonium ion, but the azo coupling product is formed when the more electrophilic 2,4-dinitrobenzenediazo-nium ion is used. 

Azo coupling reactions with phenol ethers give in some cases the expected arylazo-phenol ether. In others, however, hydrolysis of the ether bond is observed and the arylazophenol is isolated. This ambiguity has, to the best of our knowledge, never been investigated systematically. 

The reaction was also found to be inhibited by addition of dioxan and tetra-hydropyran, the rate decrease being proportional to the ether concentration. The results were rationalised by the assumption that 2 1 and 1 1 phenol ether complexes were formed, respectively. The inhibition was attributed to participation of the hydroxyl group in solvation of the halogen atom of the alkyl halide, though this seems much less likely than a straightforward modification of the electron-supplying effect of the substituent3 54. 

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