9-hydroxy-9- xanthene

Diaryl ethers 166 undergo a samarium(ii) iodide promoted intramolecular phenyl-carbonyl coupling to afford 3-formyl-9-hydroxy-9//-xanthenes in moderate yield (Equation 77) <2001SC877>. [Pg.467]

Crystalline derivatives may be prepared with xanthhydrol (9-hydroxy-xanthen), but the reagent is comparatively, expensive. Xanthhydrol reacts with primary amide,s with the formation of crystalline xanthyl-amides or 9-acylamidoxanthens ... [Pg.405]

Analog kondensiert in Essigsaure-Losung Malonsaure mit 9-Hydroxy-xanthen zu Xanthen-9-yl-malonsdure (87%)4S ... [Pg.373]

Xanthene dyes are those containing the xanthylhim [261-23-4] (la) or diben2o-y-pryan nucleus [92-83-1] (xanthene) (lb) as the chromophore with amino or hydroxy groups meta to the oxygen as the usual auxochromes. They are... [Pg.398]

For uniformity with the stmctures given in the Colourindex the ammonium radical (9) is used for the amino-substituted xanthenes and the keto form for the hydroxy derivatives. The xanthene dyes may be classified into two main groups diphenylmethane derivatives, called pyronines, and triphenylmethane derivatives (eg, (4)), which are mainly phthaleins made from phthaUc anhydride condensations. A third much smaller group of rosamines (9-phenylxanthenes) is prepared from substituted ben2aldehydes. The phthaleins may be further subdivided into the following fluoresceins (hydroxy-substituted) rhodamines (amino-substituted), eg, (6) and mixed hydroxy/amino-substituted. [Pg.399]

Most xanthene dyes are classified as basic dyes by their method of appHcation acid dyes can be produced by introduction of sulfonic acid groups. The fluoresceins, which contain carboxy and hydroxy substituents, are also acid dyes for coloration of silk. Some of the fluoresceins in which the carboxy group has been esterified, are soluble in alcohol or other organic solvents and can be classified as solvent dyes. Mordant dyes can be produced by introducing o-dihydroxy or sahcyhc acid groups (2), which when metallised can have very good lightfastness. [Pg.399]

Xanthene-2-carboxylic acid, 7-hydroxy-9-oxo-synthesis, 3, 837 Xanthenes... [Pg.923]

Eine Losung von 0,274 ml (1 mMol) 9-Hydroxy-9-phcnyl-xanthen und 0,5 ml (3,2 mMol) Triathyl-silicium-hydridin 3 ml Essigsaure wird 48 Stdn. bei 25°gehaltenunddanach mit 40 m/ Wasser versetzt. Der Niederschlag wird filtriert und aus 95%igem Athanol kristallisiert Ausbeute 0,1975 g (77% d.Th.) F 142,5-144,5°. [Pg.412]

Durochinon liefert bei der Elektrolyse an Platin 7-Hydroxy-l,4-dioxo-2,3,4a,5, 6,8,9a-heptamethyl-J,4,4a,9a-tetrahydro-xanthen (69% d.Th. Didurochinon)5 ... [Pg.643]

Erythrosine (E 127, FD C Red No. 3, Cl Food Red 14) is a xanthene dye named disodium salt of 2-(2,4,5,7-tetraiodo-3-oxido-6-oxoxanthen-9-yl)benzoate monohydrate (or disodium salt of 9-(o-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-... [Pg.607]

Henkel B, Zeng W, Bayer E. 9-Hydroxy-9-(4-carboxyphenyl)xanthene- a new linker for the synthesis of peptide amides. Tetrahedron Lett 1997 38 3511-3512. [Pg.220]

Structurally related to the triarylmethanes is the xanthene chromogen (1.30), in which two of the aryl nuclei are linked by an oxygen atom to form a pyrone ring. Similar terminal groupings (amino, hydroxy, or both) are usually present. Xanthene dyes have mainly... [Pg.12]

The systematic name of fluorescein in its quinoid form is Benzoic acid, 2-(6-hydroxy-3-oxo-3H-xanthen-9-yl)-. systematic name of... [Pg.225]

Chemical Name Mercury, (2, 7 -dibromo-3, 6,-dihydroxy-3-oxospiro (isobenzofuran-l(3H),9 -(9H)xanthen)-4 -yl)hydroxy-, disodium salt... [Pg.2182]

Erythrosine occurs as a brown powder or granules. It is principally the disodium salt of the monohydrate of 9-(o-carboxy-phenyl)-6-hydroxy-2,4,5,7-tetraiodo-3//-xanthen-3-one. It dissolves in water to give a solution red at neutrality, with a yellow-brown precipitate in acid, and with a red precipitate in base. When dissolved in concentrated sulfuric acid, it yields a brown-yellow solution that evolves iodine and a precipitate of the free acid when heated. It is insoluble in ethanol. [Pg.154]

FD C Red No. 3 is principally the monohydrate of 9-(o-carboxyphenyl)-6-hydroxy-2,4,5,7-tetraiodo-3/7-xanthen-3-... [Pg.164]

H-Pyran 6-(l-Ethyl-pentyliden)-4-methoxy-5,6-dihydro- VII/4. 195 Xanthen 4a-Hydroxy-dodecahydro-VI/4. 340, 368... [Pg.1189]

TETRABROMOFLUORESCEIN S TETRABROMOFLUORESCEIN SOLUBLE 2-(2,4,5,7-TETRABROMO-6-HYDROXY-3-OXO-3H-XANTHENE-9-YL)BENZOIC ACID, DISODIUM SALT TOYO EOSINE G 1903 YELLOW PINK... [Pg.214]

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