Trihydroxybenzenes

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 diphenylmethylene ketal prepared from a catechol (Ph2CCl2, Pyr, acetone, 12 h) or (Ph2CCl2, neat, 170°, 5 min, 59%) can be cleaved by hydrogenolysis (H2/ Pd-C, THF). It has also been prepared from a 1,2,3-trihydroxybenzene (Ph2CCl2, 160°, 5 min, 80% yield) and cleaved by acidic hydrolysis (HOAc, reflux, 7 h). ... 

Chemical Designations - Synonyms 1,2,3-Benzenetriol Pyrogallol 1,2,3-Trihydroxybenzene ChemicalFormuia l,2,3-C(H3(OH)3. 

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. 

Rieble S, DK Joshi, MH Gold (1994) Purification and characterization of a 1,2,4-trihydroxybenzene... 

Tao Y, A Fishman, WE Bentley, TK Wood (2004) Oxidation of benzene to phenol, catechol, and 1,2,3-trihydroxybenzene by toluene 4-monooxygenase of Pseudomonas mendocina KR 1 and toluene... 

Dioxygenase. Although it is not involved in the transformation of PAHs, it may be noted for the sake of completeness that a catechol intradiol dioxygenase is involved in the fission of 1,2,4-trihydroxybenzene that is formed from a number of aromatic substrates (Rieble et al. 1994). 

Brune A, B Schink (1992) Phloroglucinol pathway in the strictly anaerohicPelobacteracidigallici fermentation of trihydroxybenzenes to acetate via triacetic acid. Arch Microbiol 157 417-424. 

The degradation of resorcinol can take place by several pathways that are initiated by hydroxylation. 1,2,4-Trihydroxybenzene is degraded by (a) 1 2 dioxygenation and... 

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