Eosin sodium salt

D C RED No. 22 DISODIUM EOSIN EOSINE EOSINE SODIUM SALT EOSINE YELLOWISH EOSIN GELBLICH (GERMAN) FENAZO EOSINE XG HIDACID DIBROMO FLUORESCEIN IRGALITE BRONZE RED CL PHLOXINE TONER B PHLOX RED TONER X-1354 PURE EOSINE YY 11445 RED SODIUM EOSINATE... 

Sodium salt of eosin. Grind together in a mortar 12 g. of eosin with 2 g. of anhydrous sodium carbonate. Transfer the mixture to a 250 ml. conical flask, moisten it with 10 ml. of rectified spirit, add 10 ml. of water and warm on a water bath, with stirring, until the evolution of carbon dioxide ceases. Add 50 ml. of ethyl alcohol, heat to boiling, and filter the hot solution through a fluted filter paper (supported in a short-stemmed funnel) into a beaker, and allow to stand overnight. Filter ofiF the browiiish-red crystals of sodium eosin, wash with a little alcohol, and dry. The yield is 10 g. 

Brominating fluorescein in the presence of sodium chlorate affords the red tetrabromo derivative, whose sodium salt is known as eosine (Caro 1871). Sodium chlorate reoxidizes, evolving hydrogen bromide, to bromine which can react again ... 

Sodium Salt of Eosin.—Grind 6 g. of eosin with 1 g. of anhydrous sodium carbonate, transfer the mixture to a moderate-sized, widenecked, conical flask, moisten with a little alcohol, add 5 c.c. of water, and warm on the water bath until evolution of carbon dioxide ceases. To the aqueous solution of the sodium salt thus obtained now add 20 g. of alcohol, heat to boiling, and filter the hot solution. From the cooled filtrate there separate beautiful brownish-red crystals with metallic lustre, often only after long standing. Collect them at the pump and wash with alcohol. 

The carbodiimide mediated attachment of dye molecules, such as 5(6)-carboxyfluoresceine or rhodamine B to the model compound penylethylamine proceeds in 78 % and 63 % yields, respectively, using diisopropylcarbodiimide, three equivalents of pyridinium-p-toluenesulfonate (PPTS) and two equivalents of diisopropylethylamine (DIPEA). The above conditions are especially useful when the sodium salts of dyes are used. Examples are eosine Y, erythrosin B and phloxine B because yields of >90 % are obtained when the reactions are conducted in DMF in the presence of HOBt. ... 

The sodium salt is known in commerce as Eosin Scarlet, Safrosin, or Lutecienne. 

The acid xanthene dyes comprise Eosin (tetrabromofluorescein, formula 4.34) [79,80], Erythrosin (tetraiodofluorescein) and Rose Bengal B (formula 4.35) [79]. All these reagents are available as sodium salts. 

Eosine e-9-s9n [ISV, fr. Gk eds dawn] (1866) n. C2oH8Br405. Red acid dye used in the manufacture of lake pigments. Sodium salt of brominated fluorescein. 

Japan Red No. 230-1 Morning red Neelicol Eosine Orient Water Red 2 Orient Watger Red 2 Phlox Red Toner X 1354 Phloxine Red 20-7600 Phloxine Toner B Pure Eosine YY Red 103 Red 17255 Red No. 103 Red No. 230-1 Silk Discharge Orange 3R Simacid Eosine Y Sodium eosin Sodium eosinate Sodium eosine Spiro [isobenzofuran-1 (3H),9 -[9f/]xanthen]-3-one, 2, 4, 5, 7 -tetrabromo-3, 6 -dihydroxy-, disodium salt Symuler Eosin Toner Tetrabromofluorescein Tetrabromofluorescein D Tetrahromofluorescein S Tetrabromofluorescein soluble Toyo Eosine G Triacid Eosine Vicoacid Eosine Water Red 2... 

Some colouring matters containing chlorine, such as eosin, may leave ash containing haloid salts. In this case the solution of the colouring matter, addified with sulphuric acid, may be extracted with ether and the aqueous liquid tested for chlorine and sodium. 

Tetrahromfluoresceih and the lower brominated products come into commerce as sodium or potassium salts, and form the various brands of soluble eosins. 

The ethyl ether, in form of its sodium or potassium salt, is extensively used in silk-dyeing as spirit eosin or primerose h kalcool/ For use, the commercial product is dissolved in spirit and gradually added to the dye-bath, which is acidified with acetic acid. 

Xanthates may be determined in flotation liquids< ) by utilizing a stock solution consisting of 0-05 N sodium hydroxide, 0-1 N potassimn chloride and 0-001 M eosin. The presence of eosin counteracts the adsorption and extends the useful concentration range of 0-05 mM to 2-5 mM solutions. The anodic waves of the xanthates, corresponding to a mercury salt formation are recorded at —0-3 to —0-4 V. 

The experimental results show conclusively that the suppression of spontaneous explosion during crystallization by metathesis from solutions of soluble lead salt (usually lead acetate or nitrate) and soluble azide (usually sodium azide) is obtained by (a) rapid and thorough mixing of the solutions and (b) the use of certain additives especially hydrophilic colloids (PVA, dextrin, eosin). Amounts as small as 0.02 % of PVA completely suppressed spontaneous explosions [18]. 

There are a number of varieties of Eosin (sometimes eosine ), but the most common are Eosin B (Cl 45400/Acid Red 91) and Eosin Y (Cl 45380/Acid Red 87) the former is the sodium or ammonium salt of the dibromo derivative of dinitrofluorescein, while the latter is the disodium salt of tetrabromofluorescein. Eosin Y was discovered by Caro in 1871, Eosin B by Caro in 1875 and Baeyer in 1876 Colour Index, 1971). 

Other Names Fluorescein, 4, 5 -dibromo-2, 7 -dinitro-, disodium salt Spiro[isobenzofuran-l(3//),9 -[97/]xan-then]-3-one, 4, 5 -dibromo-3, 6 -dihydroxy-2, 7 -dinitro-, disodium salt C.I. 45400 C.I. Acid Red 91 Dibromodi-nitrofluorescein sodium Eosin B Eosin BA Eosine B Eosine BA Eosine BN Eosine BNX Eosine I Bluish Saffrosine Simacid Nitro Eosin 24669... 

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