Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

S anthraquinone

Aluminium hydroxide Unknown s Anthraquinone sulfonic acid Unknown 1... [Pg.263]

S% anthraquinone aglycones and gluco.sides, 7%-10% stilbene dcrivative.s rliaponticoside 5%, desoxyrhaponticoside. Adulterant of Rhei radix... [Pg.57]

Fieser s solution An aqueous alkaline solution of sodium anthraquinone -sulphonale (silver salt) reduced with sodium dithionite, Na2S204, and used as a scrubbing solution for partially removing O2 from, e.g., N2. [Pg.174]

S oda—Anthraquinone. A few mills worldwide use soda pulping of hardwoods. In such cases, the addition of anthraquinone is immediately justifiable in terms of increased yield and upgraded pulp quaHty. The conversion of existing kraft mills is not as simple because AQ contributes no alkalinity to the process as sulfide does, and most kraft causticizing systems would have to be expanded by about 33%. This conversion is probably not justifiable in terms of the yield gain. The greatest benefit from AQ is for new mills in which expenditures for air pollution abatement devices can be reduced. [Pg.271]

SuIfona.tlon, Sulfonation is a common reaction with dialkyl sulfates, either by slow decomposition on heating with the release of SO or by attack at the sulfur end of the O—S bond (63). Reaction products are usually the dimethyl ether, methanol, sulfonic acid, and methyl sulfonates, corresponding to both routes. Reactive aromatics are commonly those with higher reactivity to electrophilic substitution at temperatures > 100° C. Tn phenylamine, diphenylmethylamine, anisole, and diphenyl ether exhibit ring sulfonation at 150—160°C, 140°C, 155—160°C, and 180—190°C, respectively, but diphenyl ketone and benzyl methyl ether do not react up to 190°C. Diphenyl amine methylates and then sulfonates. Catalysis of sulfonation of anthraquinone by dimethyl sulfate occurs with thaHium(III) oxide or mercury(II) oxide at 170°C. Alkyl interchange also gives sulfation. [Pg.200]

Among anthraquiaoae dyes (see Dyes, anthraquinone). Acid Blue 78 [6424-75-5] C2 H25BrN20 S -Na, or Alizarin Pure Blue B, is a wool dye. Bromamine acid [116-81-4] (l-amiao-4-bromoanthraquiaoae-2-sulfonic acid), C24HgBrNO S, is a useful dye iatermediate. A number of bromo anthraquiaoae, pyrathroae, and benzanthrone dyes are known. [Pg.297]

Anthraquinone dyes are derived from several key compounds called dye intermediates, and the methods for preparing these key intermediates can be divided into two types (/) introduction of substituent(s) onto the anthraquinone nucleus, and (2) synthesis of an anthraquinone nucleus having the desired substituents, starting from benzene or naphthalene derivatives (nucleus synthesis). The principal reactions ate nitration and sulfonation, which are very important ia preparing a-substituted anthraquiaones by electrophilic substitution. Nucleus synthesis is important for the production of P-substituted anthraquiaones such as 2-methylanthraquiQone and 2-chloroanthraquiaone. Friedel-Crafts acylation usiag aluminum chloride is appHed for this purpose. Synthesis of quinizatia (1,4-dihydroxyanthraquiQone) is also important. [Pg.309]

The conditions adopted in this procedure favor the production of a-monosulfonate in a state of high purity at the expense of a high conversion of anthraquinone. A better conversion can be achieved by conducting the sulfonation at a higher temperature, or by using more oleum, but in either case there is a considerable increase in the amount of disulfonic acids formed. The extent of /3-sulfonation is not influenced greatly by the temperature, but is dependent chiefly on the amount of mercuric salt present in the solution. The amount specified corresponds approximately to the limit of solubility of the salt in the acid employed, and very little of the /3-acid is formed. As the potassium /S-sulfonate is more soluble than the a-salt, traces of this isomer are easily eliminated by crystallization. [Pg.74]

One potentially important example of CIDNP in products resulting from a radical pair formed by electron transfer involves a quinone, anthraquinone j5-sulphonic acid (23). When irradiated in the presence of the cis-syn dimer of 1,3-dimethylthymine (24), enhanced absorption due to vinylic protons and emission from the allylic methyls of the monomer (25) produced can be observed (Roth and Lamola, 1972). The phase of the polarizations fits Kaptein s rules for intermediate X... [Pg.110]

Note Monohydroxybenzene derivatives and vicinal hydroxymethoxybenzene derivatives do not react under these conditions but can be made visible by spraying afterwards with Folin-Qocalteu s reagent [1]. Flavonoids, anthraquinone derivatives and a-nitroso-B-naphthol yield a red color with alkalis alone [1]. Steroids and aromatic amines do not react [1]. [Pg.98]

Alizarin. Dissolve successively in 75 ml. of water 6 g. of potassium chlorate, 20 g. of sodium anthraquinone-p-sulphonate and 75 g. of sodium hydroxide. Transfer the mixture to a 500 ml. autoclave (compare S ion VI,4) and heat for 20 hours at 170°. After cooUng, scrape out... [Pg.981]

Dichloro-2-N-octyl-isothiazolin-3-one and 2-methylthio-4-tert-butylamino-6-cyclopropylamino-S-triazine or N,N-dimethyl-N -phenyl-N -fluorodichloromethylthio)sulfamide Anthraquinones Free halogen sources with 5,5-dimethylhydantoin,... [Pg.74]

Lemus, R. H. Skibo, E. B. Design of pyritnido[4.5-s quinazoline-based anthraquinone mimics, structure-activity relationship for quinone methide formation and the influence of internal hydrogen bonds on quinone methide fate. J. Org. Chem. 1992, 57, 5649-5660. [Pg.264]

Kanokmedhakul K, Kanokmedhakul S, Phatchana R. Biological activity of anthraquinones and triterpenoids from Prismatomeris fragrans. J Ethnopharmacol 2005 100 284-288. [Pg.224]

The relative and absolute configurations of diepoxydicarbazoles involving the 2,6-dioxa-4,8-diazaadamantane system were determined in the course of a study on indole and indole alkaloids.242 Water-soluble azo, anthraquinone, and phthalocyanine dyes which are substituted by a 4-chloro-s-triazin-2-ylamino group can be quaternized with a l-aza-3-methyl-4,6,10-trioxa-adamantane unit in aqueous medium at 40 50"C.243 Dyes mixed with... [Pg.122]


See other pages where S anthraquinone is mentioned: [Pg.263]    [Pg.736]    [Pg.66]    [Pg.343]    [Pg.346]    [Pg.20]    [Pg.150]    [Pg.263]    [Pg.736]    [Pg.66]    [Pg.343]    [Pg.346]    [Pg.20]    [Pg.150]    [Pg.312]    [Pg.364]    [Pg.186]    [Pg.402]    [Pg.396]    [Pg.80]    [Pg.445]    [Pg.93]    [Pg.4]    [Pg.480]    [Pg.186]    [Pg.767]    [Pg.405]    [Pg.545]    [Pg.73]    [Pg.171]    [Pg.388]    [Pg.427]    [Pg.306]    [Pg.235]    [Pg.385]    [Pg.384]    [Pg.472]    [Pg.52]    [Pg.90]    [Pg.103]    [Pg.120]    [Pg.101]   
See also in sourсe #XX -- [ Pg.137 ]




SEARCH



Anthraquinone

Anthraquinones

© 2024 chempedia.info