Phenol-2,4-disulfonic acid

V.l. Volkov, YA. Dobrovolsky, M.S. Nurtniev, E.A. Sanginov, E.V. Volkov, A.V. Pisareva, Charge and mass transport in the phenol-2,4-disulfonic acid-polyvinyl alcohol ion exchange membranes studied by pulsed field gradient NMR and impedance spectroscopy. Solid State Ionics 179 (2008) 148-153. 

Refs on Analysis of NG 1) Marshall 2(1917), pp 739—40 (Estimation of small quantities by reaction with phenol disulfonic acid to form. PA and colorimetric measurement against K nitrate standards) 2) Koehler et al, AnnChimAnal-ChimAppl 2, 271-2(1920) CA H 3794(1920) (Devarda method) 3) W.W. Becker, lECAnalEd 5, 152-4(1933) CA 27, 2909U933)(Redox method for NG and NGc in the presence of DNT)... 

Hadjidemetriou [25] has carried out a comparative study of the determination of nitrates in calciferous soils by the phenoldisulfonic acid and the chromotropic acid spectrophotometric methods. He used 0.02 N cupric sulfate as soil extractant. Silver sulfate was added to remove chlorides. Nitrites, if present, were eliminated by acidifying the extract with N in sulfuric acid. The phenol disulfonic acid method is subject to interference by other ions. Details of the chromotropic acid method are given below. 

Picric acid Phenol + H2S04 - phenol disulfonic acid followed by nitration... 

Titanium ions can also he used as redox catalysts for the indirect cathodic reduction of nitro compounds (417). The electroreduction is carried out in an H20-H2S04/Ti(S04)2-(Pb/Cu) system at 45 80°C under 5 20Am . Nitrobenzene, dinitrobenzene, nitrotoluene, 2,4-dinitrotoluene, 2-nitro-m-xylene, nitro-phenol, 2,4-dinitrophenol, nitrophenetole, o-nitroanisole, 4-nitrochlorotoluene, ni-trobenzenesulfonic acid, and 4,4 -dinitro-stilbene-2,2 -disulfonic acid can all be reduced by this procedure to the corresponding amino compounds (418) in good yields (Scheme 146) [513-516]. Tin... 

Bis-substitution of stilbene produces stronger fluorescence and the bis-triazine derivatives of diaminostilbenes have proved to be the most successful brighteners for cellulosics, in particular, and polyamides (60MI11200). The variety of substitution permutations in (90) is almost endless and many primary and secondary homocyclic and heterocyclic amines, thiols and phenols have been used. Synthesis of such compounds is straightforward and utilizes the convenient selectivity to substitution of cyanuric chloride. 4,4 -Diaminostilbene-2,2 -disulfonic acid condenses readily at 0-5 °C with cyanuric chloride, under slightly acidic conditions. In this case cyanuric chloride behaves as a monofunctional acid chloride and, although some by-products are unavoidable, two molecules of cyanuric chloride condense... 

Good agreement was obtained between results obtained on soil extracts by this method, the more lengthy phenolic disulfonic method and an ion-selective electrode method in the nitrate nitrogen range 3 - 200 mg/kg. The relationships between the three methods are shown in Table 6.2. There is a very close relationship between the methods the correlation coefficients are almost unity, indicating that the phenoldisulfonic acid method could be replaced with the ion-selective electrode or the chromotropic acid method. 

C. I. Direct Yellow 12, 24895 [2870-32-8] 4,4 -Diaminostilbene-2,2 -disulfonic acid is bis-diazotized with an aqueous solution of sodium nitrite at 5°C. Next, phenol is dissolved in water, and sodium hydroxide solution and soda are added. To this solution is added the above bis-diazotized solution. Then, more 30 % sodium hydroxide solution is added. On the following morning, the solution is heated to 70 °C, and after addition of 30 % hydrochloric acid, the dye is salted out with rock salt. The damp press cake, ethanol, soda, 30 % sodium hydroxide solution, and ethyl chloride are kept in a closed stirrer vessel for 24 h at 100 °C (5 - 5.5 bar). The mixture is then cooled to 70 °C and transferred at its own pressure to a distilling vessel, from which the ethanol is distilled. After being cooled to 80 ° C, the mixture is suction filtered and dried at 100 °C. 

Benzene-m>disulfonic acid is used in the preparation of phenol-m-sulfonic acid and of resorcinol. Further sulfonation of benzene-m-disulfonic acid to the trisulfonic acid is accomplished by heating the sodium salt for several hours at about 250°, in the presence of mercury, with 66 per cent oleum. 

In a glass, iron, or porcelain sulfonation vessel, 94 grams of phenol of the highest quality is heated to 100°C., and 300 grams of 100 per cent sulfuric acid is added with stirring at such a rate that the temperature remains below 110°. The mixture is heated for an hour at 100-110° to complete the sulfonation of the phenol, converting most of it to the disulfonic acid. The mixture is then cooled to 0° in an ice-salt bath, and 3.5 moles of nitric acid, in the form of 50 per cent mixed acid, is added over a period of about 3 hours. 

The reaction of di- and polysulfonic acids can usually be carried out so that the replacement of the sulfo groups by hydroxyls takes place stepwise (partial alkali fusion). Thus, phenol-m-sulfonic acid is obtained from benzene-m-disulfonic acid under mild conditions, while resorcinol is formed under more vigorous conditions (see page 144) similarly, naphthalene-l,5-disulfonie acid yields, first, l-naphthol-5-sulfonic acid, then l,5 dihydroxynaphthalene, both valuable azo dye... 

The alkali fusion of benzene-m-disulfonic acid yields resorcinol only in the absence of water. With aqueous sodium hydroxide under pressure, phenol-m-sul-fonic acid is formed, and if the temperature is increased, phenol and decomposition products are formed, but not resorcinol. The formation of some phenol as a byproduct cannot be avoided completely. ... 

This represents a two-step hydrolysis. In the first phase, it requires anhydrous reactants to avoid the formation of a-hydroxylamide, which is more difficult to convert to methacrylamide sulfate. It takes place in liquid medium, at atmospheric pressme, first at about 80 to 110°C, and then 125 to 145°C to complete the transformation, nidi residence tones of about 1 h, an HjSO /acetone cyanohydrin molar ratio of 1.5 to 2, and a molar yield of 95 to 97 per cent The main by-products are carbon monoxide and acetone disulfonic acid. It is necessary to operate in the presence of an inhibitor (phenol, phenothiazme, sulfur, etc.) to prevent the formation of polymers. 

Fig. 2. Coupling components in azo dyes. The preferred positions of coupling are indicated by arrows and the usual pH conditions are noted. (1) 1-Naphthol [90-15-3], (2) 2-naphthol [135-19-3] (3) 3-hydroxy-2-naphthanilide [92-77-3], (4) aceto acetanilide [102-01-2] (5) 3-methyl-l-phenyl-5-pyrazoline [89-25-8] (enol form) (6) 8-amino-l-naphtol-3,6-disulfonic acid [90-20-0] (H-acid) (7) phenol [108-95-2] (8) resorcinol [108-46-3] (1 and 2 indicate the first and second substitution sites) (9) 2-naphthylamine [91-59-8] (10) 1-naphthylamine [134-32-7], (11) N,N-dimethylaniline [121 -69-7] (12) barbituric acid [67-52-7] (13) Fischer s base [118-12-7] (14) 8-hydroxyquinoline [148-24-3] (15) 2,4-dihydroxyquinoline [86-95-3],...

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