PHENOXYQUINONES. 1. 2-PHENOXY-p-BENZOQUINONE AND 2-PHENOXY-5-METHYL-p-BENZOQUINONE

As a part of a study of the developing action of certain substituted catechols and hydroquinones, it was necessary to prepare 4-phenoxycatechol (III) and 2-phenoxyhydroquinone (X). The methods used to prepare these compounds are described here.f The synthesis of 4-phenoxycatechol was achieved by the following sequence of reactions: Veratrol was iodinated in carbon tetrachloride solution in the presence of a molar equivalent of silver trifluoroacetate to 4-iodoveratrol (I) in a 1326 solidified on cooling, m.p. 44-45°. Anal. Calc'd for CuHuOs: C, 73.0; H, 6.1.Found: C, 72.8; H, 6.3. 2-Phenoxyhydroquinone (X). A mixture of 28 g. of 2,5-dimethoxydiphenyl ether and 200 g. (1.4 moles) of anhydrous aluminum chloride in 100 ml. of benzene was heated under reflux on a steam-bath for two hours and then poured into ice and hydrochloric acid. The gray solid (20 g. 88%) was recrystallized from dilute acetic acid, m.p. 155°. When the method described for preparing 4-phenoxycatechol was applied to 2-phenoxyhydroquinone dimethyl ether, an 85% yield of the demethylated product was obtained. SUMMARYThe syntheses of 4-phenoxycatechol and 2-phenoxyhydroquinone are described. A method of iodination is given that should have wide application. A new demethylation procedure is reported.

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“…After recrystallization from acetic acid, it melted! at 155°, as previously reported by Ungnade and Zilch (6).…”

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confidence: 88%

THE SYNTHESIS OF 4-PHENOXYCATECHOL AND 2-PHENOXYHYDROQUINONE¹

Janssen¹,

VanAllan²,

Wilson³

1955

J. Org. Chem.

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“…Because of unfavorable solubilities, the normal potentials of the phenoxyquinones (I) and (II) and 5-methyl-2-phenoxy-p-benzoquinone have been determined polarographically in dioxane-buffer mixtures. While the absolute values are considerably affected by the change in solvent, potential differences remain essentially unaltered and the potential-lowering effects of 0.126, 0.132, and 0.135 v.8 for the phenoxyl groups in the three compounds compare favorably with the value of 0.131 v. determined from the normal potential of 2-phenoxybenzoquinone in alcoholic solution (1).…”

mentioning

confidence: 76%

“…bromine. 1,4-Dimethoxy-2-phenoxybenzene (1) is the only product of the reaction regardless of whether the Ullmann reaction is run with solvents or without.…”

mentioning

confidence: 99%

“…In view of the similarity between the quinone A-band and the high intensity band in C=C-C=0 (7) it is to be expected that quiñones will show regular bathochromic shifts of the A-bands when substituents are introduced. A survey of published ultraviolet absorption spectra (1,7) shows A-band shifts per substituent for p-benzoquinones containing nucleophilic substituents which are roughly proportional to the potential-lowering of the substituents. Only the values due to phenoxyl constitute an exception.…”

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confidence: 99%

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Phenoxyquinones. Ii. The Diphenoxyquinones

Ungnade¹,

Zilch²

1951

J. Org. Chem.

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“…o-Chlorophenol (256 grams, 2 moles), phenol (940 grams, 10 moles), potassium hydroxide (336 grams, 6 moles), and copper powder (6.3 grams) were heated at 195°C for 6 hr, cooled, poured onto a 2-liter solution of 15% hydro-110 Journal of Chemical and Engineering Data, Vol. 17 (19). m-Phenoxyphenol ( 16), bp 120-25°C/0.25 mm, n% 1.5975 (79% yield).…”

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confidence: 99%