Phenol Red, Sodium Salt

Other Names Phenol, 4,4 -(3H-2,l-benzoxathiol-3-ylidene)fcli-, 5,5-dioxide, monosodium salt 3H-2,l-Benzoxathiole, phenol deriv. Phenol red sodium Phenol red, sodium salt Phenolsulfone-phthalein sodium 

CA Index Name Phenol, 4,4 -(l,l-dioxido-3H-2,l-benzoxathiol-3-ylidene) t5-, monosodium salt CAS Registry Number 34487-61-1 Merck Index Number Not listed Chemical Structure 

Chemical/Dye Class Sulfonephthalein Molecular Formula Ci9Hi305SNa Molecular Weight 376.36 pH Range 6.8-S.4 

Physical Form Shiny dark-red crystals Solubility Soluble in water, ethanol UV-Visible (7. ,ax) 423 run, 557 nm Melting Point 285°C Synthesis Synthetic methodi  

Major Applications Sensor,4 optical device, paints, sterilization process, fertilizer, detecting viable cells, gastrointestinal mucosa,antibacterial agent,n drugs,i2pharmacologyi3 Safety/Toxicity Toxic blocking activityi  

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Phenol Red sodium salt [34487-61-1] yellow-red-violet 0.05 (in water)... 

Part bromthymol blue (sodium salt) 0.1% in water 1 phenol red (sodium salt) 0.1% in water 7.5 ti (1 Dirty green at 7.2 pale violet at 7.4 intense violet at 7.6 excellent indicator... 

To a mixture of 10 g. of the compound and 3-5 ml. of 33 per cent, sodium hydroxide solution in a test-tube, add 2-5 ml. of 50 per cent, chloroacetic acid solution. If necessary, add a little water to dissolve the sodium salt of the phenol. Stopper the test-tube loosely and heat on agently-boiling water bath for an hour. After cooling, dilute with 10 ml. of water, acidify to Congo red with dilute hydrochloric acid, and extract with 30 ml. of ether. Wash the ethereal extract with 10 ml, of water, and extract the aryloxyacetic acid b shaking with 25 ml. of 5 per cent, sodium carbonate solution. Acidify the sodium carbonate extract (to Congo red) with dilute hydrochloric acid, collect the aryloxyacetic acid which separates, and recrystallise it from hot water. 

An additional useful test is to distil the acid or its sodium salt with soda lime. Heat 0.5 g. of the acid or its sodium salt with 0 2 g. of soda lime in an ignition tube to make certain that there is no explosion. Then grind together 0-5 g. of the acid with 3 g. of soda hme, place the mixture in a Pyrex test-tube and cover it with an equal bulk of soda hme. Fit a wide dehvery tube dipping into an empty test-tube. Clamp the tube near the mouth. Heat the soda lime first and then the mixture gradually to a dull-red heat. Examine the product this may consist of aromatic hydrocarbons or derivatives, e.g., phenol from sahcyUc acid, anisole from anisic acid, toluene from toluic acid, etc. 

Silver salt, AgCgH4N02, almost black, but dk blue in transmitted light, fine crysts, expl on heating or on contact with acids Sodium salt, NaCgK4N02, red-grn shiny Ifts, expl on heating Benzoquinone-1,4-monooxime [called Benzo-chinon-(1.4)-monoxim p-Ohinon-monoxim or "p -Nitroso-phenol in Ger],, CH=CH. 

The amine is titrated with hydrochloric acid and sodium nitrite in very dilute solution, and the resulting diazonium salt is coupled with an accurately known amount of a phenol, usually SchaefiFer salt. With other compounds, such as H acid, amino R acid, etc., one sample is diazotized and another is coupled with diazotized aniline or other amine. Under some circumstances it is possible to determine two substances in mixture if one of them reacts much more rapidly than the other. Thus, with a little practice, one can determine quite accurately both G salt and R salt in mixtures of.the two. R salt couples very rapidly with diazotized aniline producing a red dye, while G salt couples more slowly and gives a yellow dye. A large number of other special methods are available which permit the determination of the individual constituents in mixtures. 

On this evidence Schopf was unable to advance a structural formula for flavothebaone. It was, however, clear that the a. /3-unsaturated ketone system is in conjugation with one of the phenolic groups as, though the sodium salt of flavothebaone is red, the sodium salt of dihydroflavothebaone is colourless [2],... 

Whole serum does not bind phenol red below a critical albumin concentration of 1.6 g%. Above this critical value, dye is bound in direct proportion to the amount of albumin in excess of the critical value. In jaundice the critical value is elevated. These results were taken to indicate that some binding sites in whole serum are occupied by, for example, bilirubin, bile acids, or fatty acids (B27). Bile salts reduce the binding of BSP (All, A14, R18a). This effect may be due to the detergent properties of bile salts because Teepol has been found to have a similar effect (A14). Binding of rose bengal was not affected by sodium dehydro-cholate or by BSP (E4). 

The dye is a red crystalline compound which forms salts with acids and bases. The sodium salt is the yellow coralUn of commerce The dye is prepared by heating a mixture of phenol, sulphuric acid, and oxalic acid. 

There are numerous variations on this medium using mannitol instead of lactose, teepol or sodium lauryl sulfate instead of bile salts, and alternative indicators such as Phenol Red. However, all the tests are based on the ability of coliforms to grow in the presence of some inhibitor, and ferment lactose or mannitol to acid and gas, the acid changing the colour of the indicator. 

See Sodium C14-17 alkyl sec sulfonate Sulfonic acids, C14-C18-alkane hydroxy and C14-C18-alkene, sodium salts. See Sodium C14-18 olefin sulfonate Sulfonic acids, C9-C22-sec-alkane, sodium salts. See Sodium C9-22 alkyl sec sulfonate Sulfonic acids, petroleum, barium salts. See Barium petroleum sulfonate Sulfonic acids, petroleum, calcium salts. See Calcium petroleum sulfonate Sulfonic acids, shale oil, sodium salts. See Sodium shale oil sulfonate Sulfonphthal. See Phenol red 1,1 -Sulfonylbis (4-aminobenzene). See 4,4 -Diaminodiphenyl sulfone 3,3 -Sulfonylbis (aniline). See 3,3 -Diaminodiphenyl sulfone 4,4 -Sulfonylbisaniline 4,4 -Sulfonylbisbenzamine p,p-Sulfonylbisbenzamine p,p-Sulfonylbisbenzenamine. See 4,4 -Diaminodiphenyl sulfone 1,1 -Sulfonylbisbenzene. See Diphenyl sulfone... 

Preparatiovi of the azo dyes 10 mg phenol are dissolved ini—2 ml 0.1 N sodium hydroxide 150 mg Fast Red AL Salt (Firm 56) are then added, followed by 20 ml water. After 30 min, the reaction mixture is acidified with a little 2N hydrochloric acid and extracted with 20 ml chloroform. The extract is washed with water and can then be used directly in TLC. 

Xanthene dyes can be either acidic or basic. Acid xanthenes are known to exist in two tautomeric forms. The phenolic type, or fluorans, are free-acid structures such as D C Orange No. 10 (23b) and D C Red No. 21 (23c). Most have poor water solubility. In contrast to these, the quinoids or xanthenes are usually the highly water-soluble sodium salt counterparts of the fluorans such as D C Orange No. 11 (24) and D C Red No. 22 (27a). 

Other compounds (D-glucose hypoxantine (sodium salt) linoleic acid lipolic acid phenol red putrescine thymidine and Na-pyruvate). 

Phthattc acid (a) In a dry test-tube warm a little of the free acid or one of its salts with an equal weight of phenol and 2 drops of concentrated sulphuric acid. Cool the tube carefully, dissolve the contents in water, and add an excess of dilute aqueous sodium hydroxide to the solution. A bright red colour indicates the formation of a sodium salt of phenolphthalein. 

Add 1 g of the phenol to 1 5 g of chloracetic acid and 5 ml of 30% sodium hydroxide solution. Addition of a little water may be necessary to dissolve the sodium salt of the phenol. Boil for 30 minutes (60 minutes may be required in some cases). Cool, acidify to Congo Red with 2N hydrochloric add, and extract with ether. Wash the ethereal solution with water, then with dilute sodium carbonate solution into which the aryloxyacetic acid passes. (The naphthoxyacetic adds may be predpitated at this stage as their sodium salts. The precipitate should be removed and addified to liberate the derivative.) Addify the alkaline extract and recrystallize the predpitated product from water. As a further check, the equivalent weight of the derivative may be determined (as for carboxylic acids, page 123). 

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