Trihydroxybenzene derivatives

The mechanism of the reaction has not yet been elucidated it is assumed that 1,2-dihydroxybenzene is oxidized to quinone and vicinal trihydroxybenzene derivatives to hydroxyquinones [1]. 

Trihydroxybenzene derivatives lb 179,180 Triiodobenzoic acid la 45 Triiodothyronine lb 76 Trimethazone lb 280... 

Another class of phenol-binding pyridines has been synthesized by Vogtle (Ebmeyer and Vogtle, 1989 Seel and Vogtle, 1992). In the bimacrocycles [69], those phenols were especially well bound which form hydrogen bonds to all three bipyridine units, for example 1,3,5-trihydroxybenzene derivatives. 

Metal salts can be used in two ways. First, pretreatment with a trihydroxyben-zene compound such as pyrogallol [87-66-1] is followed by treatment with an ammoniacal silver salt solution. This allows rapid dyeing due to the formation of metallic silver and oxidation products of the trihydroxybenzene derivative. If pre-treatment is performed with thiosulfate instead of a benzene derivative, the process yields unstable silver thiosulfate and finally black silver sulfide. 

The total synthesis of (-)-(R)-MEM-protected arthrographol was accomplished by G.L.D. Krupadanam et al." authors used sequential Viismeier reaction/Dakin oxidation to prepare a 1,2,4-trihydroxybenzene derivative. 

It reacts chemically as if it were either 1,3,5-trihydroxybenzene or the triketone of hexa-hydrobenzene. The trialkyl derivative of the hydroxy-form or the trioxime of the keto-form can be obtained from phloroglucinol by reacting in a suitable manner. In certain cases derivatives of the two forms are interchangeable. Used in printing, photography, adhesives, pharmaceuticals. 

The synthesis of 2,4-dihydroxyacetophenone [89-84-9] (21) by acylation reactions of resorcinol has been extensively studied. The reaction is performed using acetic anhydride (104), acetyl chloride (105), or acetic acid (106). The esterification of resorcinol by acetic anhydride followed by the isomerization of the diacetate intermediate has also been described in the presence of zinc chloride (107). Alkylation of resorcinol can be carried out using ethers (108), olefins (109), or alcohols (110). The catalysts which are generally used include sulfuric acid, phosphoric and polyphosphoric acids, acidic resins, or aluminum and iron derivatives. 2-Chlororesorcinol [6201-65-1] (22) is obtained by a sulfonation—chloration—desulfonation technique (111). 1,2,4-Trihydroxybenzene [533-73-3] (23) is obtained by hydroxylation of resorcinol using hydrogen peroxide (112) or peracids (113). 

Neither the mechanism by which benzene damages bone marrow nor its role in the leukemia process are well understood. It is generally beheved that the toxic factor(s) is a metaboHte of benzene (107). Benzene is oxidized in the fiver to phenol [108-95-2] as the primary metabolite with hydroquinone [123-31-9] catechol [120-80-9] muconic acid [505-70-4] and 1,2,4-trihydroxybenzene [533-73-3] as significant secondary metabolites (108). Although the identity of the actual toxic metabolite or combination of metabolites responsible for the hematological abnormalities is not known, evidence suggests that benzene oxide, hydroquinone, benzoquinone, or muconic acid derivatives are possibly the ultimate carcinogenic species (96,103,107—112). 

The blue dye (47), formed from the autoxidation of 4-/V,TV-di methyl-amino-2-hydroxyaniline, is the oxygen analogue of methylene blue. The autoxidation of 1,2,4-trihydroxybenzene, carried out in the presence of ammonia, gives the hydroxyphenoxazinone dye (48) via a 2,4-dihydroxyani-line intermediate (Scheme 17). Many types of phenoxazines, phenazines, and phenoxazinium salts can be obtained by autoxidation of polyhydroxyben-zenes and their amino derivatives. Some autoxidative dyes may give poly-... 

PVC, polyamides, unsaturated crosslinked polyesters, ABS, and wood . Di- and tri-benzotriazole photostabilizers, such as (874) and (875) are synthesized from 2-nitro-benzenediazonium salts and an excess of 1,3-dihydroxybenzene or 1,3,5-trihydroxybenzene <85Mi 40i-0l>. The dibenzotriazole derivatives (874b and 875b) can be used as polymerizable acrylic UV absorbers <84PB237>. A few or/Ao-urethane and -trimethylsilane substituted 2-phenylbenzotriazoles (876 and 877) show similar photostabilization activity . Weather resistance of low-density polyethylene is improved by the addition of a benzotriazole-type photostabilizer <90M140i-04>. 

As a first step toward a dopamine-jS-hydroxylase mimic, basket-shaped receptor 17 was functionalized with two sets of bis-[2-(3,5-dimethyl-l-pyra-zolyl)ethyl]amine ligands to give compound 35 (see Scheme 5). Reaction of 35 with Cu(C104,)2-6H20 yielded complex 36 which was fully characterized [39], Ligand system 35 binds dopamine derivative 37 and phloroglucinol (1,3,5-trihydroxybenzene) with association constants of = 60 and 3500 respectively. The affinity of the Cu(I) analogon of 36 for 37 was very similar to that of 36 itself and amounted to Ka = 60 M L Resorcinol is bound in the cavity of the Cu(I) complex with a Xj-value of 2(XX) M". ... 

Hydroxyhydroquinone (24) forms colorless plates from diethyl ether when freshly prepared. It occurs in many plants and trees in the form of ethers, quinonoid pigments, coumarin derivatives, and complex compounds. Sponges from the coastal waters of Florida have been found to contain small amounts of 1,2,4-trihydroxybenzene and traces of 2,2, 4,4, 6,6 -hexahydroxybiplienyl (25) (78). The benzenetriol has also been isolated from tobacco leaves and tar from tobacco smoke (79). Hydroxyhydroquinone has strong reducing properties. Applications have been suggested in the synthesis of agricultural... 

Antiseptic plant-derived phenols include phenol (Phe-OH, hydroxybenzene, carbolic acid), />-cresol (4-methylphenol), catechol (1,2-dihydroxybenzene), resorcinol (1,3-dihydroxybenzene) and pyrogallol (1,2,3-trihydroxybenzene). Other simple phenols with antimicrobial properties include some related to benzoic acid (benzenecarboxylic acid), namely salicylic acid (2-hydroxybenzoic acid), ginkgoic acid (2-hydroxy-6-(pentadec-8-enyl)benzoic acid), gentisic acid (2,5-dihydroxybenzoic acid), pyrocatechuic acid (3,4-dihydroxybenzoic acid) and gallic acid (3,4,5-trihydroxybenzoic acid). Other plant-derived phenol-related compounds include 4-methylcatechol, 1,3-dihydroxy-5-(heptadec-12-enyl)benzene, hydroquinone (1,4-dihy-droxybenzene), 1,4-dihydroxy-2-geranyl (di-isoprenyl)benzene and 4-methoxybenzaldehyde (/>-anisealdehyde). 

A facile generation of o-quinone methides by the fluoride-induced desilylation of o-silyloxybenzyl derivatives is the key step in a synthesis of a range of chromans, including those which contain part of the puupehedione structure <06T6012>. A formal synthesis of puupehedione is based on a Ti-catalysed cyclisation of epoxypolyenes <06EJO4115>. A quinone methide is also involved in a synthesis of robustadials A and B from 2,4,6-trihydroxybenzene-l,3-dicarboxaldehyde, 3-methylbutanal and (-)-P-pinene. The... 

HydroxylatUm of resorcinol ethers Methyl or THP ethers of resorcinol are oxidized regioselectively by w-chloroperbenzoic acid in CH2CI2 at 0° to derivatives of 1,2,4-trihydroxybenzene in yields of 55-80%. 

Although trihydroxybenzenes and their derivatives have been isolated from the oxidation products of lignins, humic acids, and land-derived marine sediments (5, 17, 23, 24, 27), it was found that 2,6-dimethoxy-... 

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