Quinol hydroxy

In addition to the above, Grignaid s leagent has been utilised m preparing olefines, etheis, ketonic esters, hydroxy-acids, quinols, amides, hydroxylammes, c., for details of wliicti books of reference must be consulted ... 

Attempts have been made to deduce the structure of the predominant form of a potentially tautomeric compound from the shifts which occur in the ultraviolet spectrum of the compound in question on passing from neutral to basic or acidic solutions. The fact that no bathochromic shifts were observed for 2- and 4-hydroxy quinoline and 1-hydroxyisoquinoline under these conditions was taken as evidence that they existed in the oxo form [similar work on substituted quinol-4-ones led to no definite conclusions ]. A knowledge of the dissociation constants is essential to studies of this type, and the conclusions can, in any case, be only very tentative. A further dif-... 

Recently, many investigators have extended the early observations that the ultraviolet spectra of - and y-hydroxypyridines resemble those of their A -methyl (not the 0-methyl) derivatives. This spectral resemblance is found both in aqueous solutions and in solutions of solvents with low dielectric constants, e.g., quinol-4-one in benzene, indicating that these compounds exist predominantly in the oxo form under all conditions. These data are summarized in Table I. In contrast, 4-hydroxyquinoline-3-carboxylic acid has been tentatively concluded to exist in the hydroxy form %- pjTid-2-one-4-carboxylic acid has also been formulated as a hydroxy compound, but this has been disputed. ... 

In 1951, Witkop et al. interpreted the infrared spectra of quinol-2-and -4-ones to favor the oxo formulation. Since then, many investigators, especially Mason, have reported that potential a- and y-hydroxy compounds show infrared absorption bands in the vN—H (3500-3360 cm ) and vC—O (1780-1550 cm ) regions of the spectrum and, hence, exist predominantly in the oxo form references to this work appear in Table I. A study of the bands which occur in the NH-stretching region of the infrared spectra of a series of substituted pyrid-2-ones and quinol-2-ones also supported an oxo formulation for these compounds. Detailed band assignments have been published for pyrid-2- and -4-one. Mason has reported that solutions of j8-hydroxy compounds in chloroform or carbon tetrachloride show... 

The pKa method was first used by Tucker and Irvin to determine the proportion of the tautomers of quinol-4-one present at equilibrium and was subsequently applied to many other potentially tautomeric hydroxy compounds " these results are summarized in Table I. 

It is clear from the preceding comments that there is no absolute distinction between the oxygenase activities mediated by dioxygenases. This is even less clear for heteroarenes than it is for carbocyclic compounds. An illustrative example is provided by Pseudomonas putida strain 86 in which 8-hydroxy-quinol-2-one is produced from quinol-2-one (Rosche et al. 1997). 

Reports of [ 2 + 2] cycloaddition of nitrogen containing heterocycles to alkenes are so numerous that attention can be drawn here to only a few. Recent examples include the acetone-sensitized photoaddition of 4-oxazolin-2-one (248) to ethylene to give the cis-adduct 249,203 the photocycloadditions of N-substituted imidazoles to acrylonitrile204 and of N-methyl-4-hydroxy-quinol-2-one to cyclohexene,205 and the photoaddition of pentafluoro-pyridine to ethylene to give the 1 1- and 1 2-adducts 250 and 251,... 

DETERMINATION OF IRON (III) AS THE 8-HYDROXY QUINOLATE COMPLEX [IRON (III) OXINATE]... 

From the hind gut of Cetonia aurata an Actinomyces species was isolated which produces the new cytotoxic epoxy quinoles [190] named cetoniacytone A 90 and B 91. In addition, the structurally related aromatic compounds 2,5-di-hydroxy-4-hydroxymethylacetanilide 92 and 2,5-dihydroxy-4-methoxymeth-ylacetanilide 93 were found in minor amounts. 

Synonyms AI3-00072 Arctuvin p-Benzenediol 1,4-Benzenediol Benzohydroquinone Benzoquinol Black and white bleaching cream BRN 0605970 CCRIS 714 Dihydroxybenzene jO-Dlhydroxybenzene 1,4-Dihydroxybenzene p-Dioxobenzene EINECS 204-617-8 Eldopaque Eldoquin HQ Hydroquinol Hydroquinole a-Hydroquinone p-Hydroquinone 4-Hydroxy-phenol p-Hydroxyphenol NC1-C55834 NSC 9247 Quinol p-Quinol Quinone Tecquinol Tenox HQ Tequinol UN 2662 USAF EK-356. 

Quercetin and many 3-hydroxylated flavones, particularly those containing o- or />-quinol structure at ring C, such as (66), are strong antioxidants for unsaturated fatty acids and lipids of vegetable tissues [349-352]. The effect of antioxidant action is decreased when some of the hydroxy groups are methylated [353],... 

This synthesis, by a purely chemical route, confirmed the structure of the thermally stable 2-acetoxy-isomer 3, since the 4-isomer (4), which can be produced from the 4-hydroxyquinol derivative by acetylation with acetanhydride and pyridine, rearranges at 100° in organic solvents to give 3 (see p. 155). On the contrary, the thermodynamic structures of methyl- or ethyl-ethers or the hydroxy quinol derivatives (the last two are only known as the 4-substituted quinol derivatives) are the 4-substituted quinols. Table 15 gives some physical data of the two isomeric 2,4,6-triphenyl-quinol derivatives. 

SYNS HYDROXYHYDROQUINONE HYDROXY-QUINOL OXYHYDROCHINON (GERMAN) OXYHYDROQUINONE 1,2,4-TRIHYDROXYBENZENE... 

SYNS BIOQUIN BIOQUIN 1 BIS(8-QUINOUNATO)COPPER BIS(8-QUINOLINOL-ATO)COPPER BIS(8-QUINOLINOLATO-NLo )-COPPER CELLU-QUIN COPPER-8 COPPER HYDROXYQUINOLATE COPPER-8-HYDROXY-QUINOLATE COPPER-8-HYDROXYQUINOLINATE COPPER-8-HYDROXYQUINOLINE COPPER OXINATE COPPER (2-I-) OXINATE COPPER OXINE... 

SYNS DIIODOHYDROXYQUIN DIIODOHYDROXYQUINOLINE 5,7-DIIODO-8-HYDROXYQUINOLINE 5,7-DIIODO-OXINE DIIODOQUIN 5,7-DIIODO-8-QUINOLINOL DINOLELNE DIODOQUIN DIODOXYLIN DI-QUINOL DIREXIODE DISOQUIN DYODIN EMBEQLTN ENTEROSEPT FLORAQUIN FLUORAQUIN 8-HYDROXY-5,7-DIIODOQUINOLINE lODOQUINOL lOQUIN SUSPENSION LANODOXIN MOEBIQUIN QUINADOME SEARLEQUIN SEBAQUIN SS 578 YODOXIN ZOAQUIN... 

Solvent evaporation Precipitation reactions can be controlled by use of mixed solvents. Slow evaporation of acetone from a buffered water-acetone solution produces results similar to PFHS in the precipitation of aluminum 8-hydroxy-quinolate. 

Hydro-quinol, 1-4-Di-hydroxy Benzene.—The third isomeric dihydroxy benzene, viz., the para compound, i-4-di-hydroxy benzene, is known as hydro-quino or hydro-quinone. The latter name is derived from its relation to quinone (p. 636) from which it is obtained on reduction and which it yields on oxidation. Both hydro-quinol and quinone derive their names from the fact that they are obtained by the oxidation of quinic acid, an acid derived from the alkaloid quinine. The phenol is found in various plants or may be obtained from them by the hydrolysis of glucosides present, e.g., arbutin, which is a glucoside hydrolyzing into glucose and hydro-quinol. 

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