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Of phloroglucinol

Gunzherg s reagent (detection of HCl in gastric juice) dissolve 4 g of phloroglucinol and 2 g of vanillin in 100 mL of absolute alcohol use only a freshly prepared solution. [Pg.1191]

Much work on the hydroperoxidation of triisopropylbenzene to make phloroglucinol, similar to the process of phenol from cumene, has been reported (149—155). The shortest route is based on readily available 4-chlororesorcinol. World production of phloroglucinol is estimated to be in excess of 200 metric tons aimuaHy (156). [Pg.384]

Grades and Specifications. Two grades of phloroglucinol, ie, grades 2 and pure, are offered in the United States by Haake, Inc., who resell material made by Fisons (Table 1). The product discolors slowly on exposure to light. [Pg.384]

The use of phloroglucinol and its derivatives as developer for light-sensitive planographic plates and for other photographic purposes has been described (163—167). [Pg.384]

Alkanoyl esters of phloroglucinol, eg, phloroglucinol trisheptanoate, are high temperature-resistant lubricants and high performance fluids (194). An aqueous solution of phloroglucinol (or of several of its simple derivatives) is used as a corrosion-resistant coating on galvanized sheet (195). The alkaU or... [Pg.385]

In the first of these, the key step in the synthetic sequence involves an oxidative phenol coupling reaction patterned after the biosynthesis of the natural product. Preparation of the moiety that is to become the aromatic ring starts by methyla-tion of phloroglucinol (5) with methanolic hydrogen chloride to give the dimethyl ether (6). Treatment of that intermediate with sulfuryl chloride introduces the chlorine atom needed in the final product (7). [Pg.314]

There are also methods based on the detection of aldehydic substances, for the typical odor and flavor of rancidity seem to be associated with the liberation of aldehydic materials during the oxidative deterioration. The Kreis test (18), perhaps the best known of these methods, consists of treating the fat with concentrated hydrochloric acid and a solution of phloroglucinol. The red color formed is attributed to a condensation product of epihydrin aldehyde with phloroglucinol. Historically, the chief difficulty with this method has been that fats which are not rancid will often give a positive Kreis test. It has been shown that if this test is quantitatively correlated with the induction period... [Pg.56]

A solvent-free synthesis of flavones was recently reported by microwave-assisted reaction of phloroglucinol 231 and differently substituted /1-ketoesters 232 [148]. The reaction was simply carried out by mixing the phenol and the ester in an open test tube followed by irradiation for 2-3 min. The internal temperature reached 240 °C and yields were in the range from 68 to 96%. Scheme 85 describes the application of this procedure to the synthesis of the natural product chrysin 233. [Pg.255]

An (emf) study of the ferricyanide oxidation of phloroglucinol revealed kine-... [Pg.434]

The chemical characteristics of the proanthocyanidins were elucidated by total oxidation and partial degradation in the presence of phloroglucinol followed by HPLC analysis. The native extract of proanthocyanidins contained (+) gallocatechin, (-) epigallocatechin, (h-) catechin, and (-) epicatechin units. ... [Pg.525]

Walker JRL, BG Taylor (1983) Metabolism of phloroglucinol by Eusarium solani. Arch Microbiol 134 123-126. [Pg.90]

Reductases play a cardinal role in the anaerobic degradation of diverse aromatic compounds, for example, (a) the reduction of benzoyl-CoA that is a prelude to the fission of the ring (Harwood et al. 1999) (Chapter 8, Part 3) and (b) the degradation of phloroglucinol via dihydrophloroglucinol to acetate and butyrate (Haddock and Ferry 1989, 1993) (Chapter 8, Part 4). [Pg.164]

Haddock JD, JG Ferry (1989) Purification and properties of phloroglucinol reductase from Eubacterium oxidoreducens G-41. J Biol Chem 264 4423-4427. [Pg.166]

The oxime of phloroglucinol explodes rather violently at 155°C. See other oximes... [Pg.795]

Fig. 7. Process intensification and adverse thermal destruction effects of the aqueous Kolbe-Schmitt synthesis of phloroglucinol using high-p,T processing. (Courtesy of Wiley-VCH)... Fig. 7. Process intensification and adverse thermal destruction effects of the aqueous Kolbe-Schmitt synthesis of phloroglucinol using high-p,T processing. (Courtesy of Wiley-VCH)...
SCHUZ, R., HELLER, W., HAHLBROCK, K., Substrate specificity of chalcone synthase from Petroselinum hortense formation of phloroglucinol derivatives from aliphatic substrates, J. Biol. Chern., 1983,258, 6730-6734. [Pg.221]

For phloroglucinolysis, a solution of 0.1 N HCl in MeOH, containing 50 g/L phloroglucinol and 10 g/L ascorbic acid, is prepared. The PA of interest is reacted in this solution at 50°C for 20 min and then combined with 5 volumes of 40 mM aqueous sodium acetate to stop the reaction. After acid-catalyzed cleavage in the presence of phloroglucinol, the fraction is depolymerized and the terminal subunits released as flavan-3-ol monomers and the extension subunits released as phloroglucinol adducts of flavan-3-ol intermediates. These products are then separated and quantified by HPLC [25]. [Pg.40]

Shimokoriyama M (1957) Interconversion of chalcones and flavanones of phloroglucinol-type structure. J Am Chem Soc 79(15) 4199-4202... [Pg.90]

Phloroglucinol (25) is more susceptible to oxidation than both phenol and resorcinol. However, its direct nitration to 2,4,6-trinitrophloroglucinol (27) can be achieved by the slow addition of a nitrating agent composed of concentrated sulfuric acid and concentrated nitric acid to a solution of phloroglucinol dihydrate in concentrated sulfuric acid between 0 and 10 °C (72 Acetylation of phloroglucinol (25) yields the triacetate (26) which moderates... [Pg.133]

Trinitrophloroglucinol has been synthesized via the nitrosation of phloroglucinol followed by nitric acid oxidation. The direct nitration of phloroglucinol must be conducted at subambient temperature to avoid excessive oxidation, and even then, the yield rarely exceeds 70... [Pg.144]


See other pages where Of phloroglucinol is mentioned: [Pg.377]    [Pg.383]    [Pg.383]    [Pg.384]    [Pg.384]    [Pg.384]    [Pg.384]    [Pg.385]    [Pg.385]    [Pg.206]    [Pg.124]    [Pg.449]    [Pg.450]    [Pg.560]    [Pg.81]    [Pg.15]    [Pg.79]    [Pg.152]    [Pg.201]    [Pg.171]    [Pg.40]    [Pg.133]    [Pg.266]    [Pg.62]    [Pg.64]    [Pg.74]   
See also in sourсe #XX -- [ Pg.319 ]




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