Naphthalene--sulphonic acid

A very elegant process for the direct preparation of the free naphthalene-/3-sulphonic acid from its components has been described by 0. N. Witt (Ber., 1915, 48, 751). It is specially recommended as an alternative to the process described above. 

SULPHANILIC ACID FROM ANILINE AND SULPHURIC ACID 

Pure concentrated sulphuric acid (100 g.) and freshly distilled aniline (31 g. =0-33 mole) are gradually mixed with shaking in a dry flask and the mixture is heated at 180°-190° in an oil bath until sodium hydroxide no longer liberates aniline from a sample diluted with water (four to five hours). The reaction mixture is cooled somewhat and then poured with stirring into cold water. Sulphanilic acid crystallises, is collected at the filter pump, washed with water, and recrystallised from water with addition of animal charcoal. Yield 30-35 g. 

On a technical scale aniline is heated with one mole only of H2S04, i.e. as acid sulphate the temperature is about the same as that given above. (The baking process.) Compare this process, which can also be used in the laboratory, with that here described. 

2 4-DINITRO-a.NAPHTHOL-7-SULPHONIC ACID 1 (Naphthol Yellow S) 

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Neville-Wintber acid The trivial name given to 4-hydroxy-1-naphthalene sulphonic acid. 

Schaffer s acid, CioHg04S. 2-hydroxy-7-naphthalene sulphonic acid. Obtained by sulphonating 2-naphthol with a small amount of sulphuric acid at a higher temperature than is used for the preparation of crocein acid. A valuable dyestuff intermediate. 

Supplement (combined with Volume XII) XI, 2nd 1933 1605-1739 2. Sulphonic acids Benzenesulphonic acid, 26. p-Toluenesulphonic acid, 97. Naphthalene - sulphonic acid, 155. Hydroxy-Sulphonic acids Phenol-sulphonic acid, 234. Naphthol-sulphonic... 

Naphthol Yellow S (citronin A, flavianic acid sodium salt, 8-hydroxy-5,7-dinitro-2-naphthalene sulphonic acid disodium salt) [846-70-8] M 358.2, dec on heating. Greenish yellow powder soluble in H2O. The free sulphonic acid can be recrystd from dil HCl (m 150°) or AcOH-EtOAc (m 148-149.5°). The disodium salt is then obtained by dissolving the acid in two equivalentss of aqueous NaOH and evaporating to dryness and drying the residue in a vacuum desiccator. The sodium salt can be recrystd from the minimum volume of H2O or from EtOH [Dermer and Dermer JACS 61 3302 1939]. 

Anilino-8-naphthalene sulphonic acid Nonfluorescent, but gives fluorescent product... 

Water dispersible Naphthalene sulphonic acid - Dispersing agents... 

Naphthalene sulphonic acid -formaldehyde condensates Dispersants... 

Tamol Series Naphthalene sulphonic acid condensates... 

Lantz [23 a] has studied the nitration of naphthalene sulphonic acids (mono-, di- and tri-sulphonic acids). He stated that no displacement of the sulphonic groups with nitro groups occurs. By using nitrating concentrated mixtures he was able to introduce nitro groups so that the number of both S03H and N02 groups reached a maximum of four. 

Naphthalene like benzene is readily sulphonated by the direct action of sulphuric acid. When the reaction takes place at moderate temperatures, about 80°, the product is mostly the alpha compound while at higher temperatures, about 160°, the beta compound is formed, the alpha-naphthalene sulphonic acid being transformed into its beta isomer at this temperature. 

Synthesis from Naphthalene Sulphonic Acids.— The simplest method of synthesis is from the corresponding naphthalene sulphonic acid by fusion with potassium hydroxide. 

By fusion of naphthalene sulphonic acids with potassium cyanide the corresponding cyano naphthalenes are obtained. These compounds are nitriles of naphthalene acids. The mono-carboxyl acids are known as naphthoic acids while the di-carboxyl acids are termed naphthalic acids. The naphthoic acids are similar to benzoic acid and the naphthalic acids are like the phthalic acids. The naphthalic acid... 

Although lipophilic and able to diffuse across the cell membrane TH can enter cells more rapidly by facilitated transport systems that tend to be specific for T4 or T3. Based on studies on isolated hepatocytes and RBCs, TH uptake in fish can be blocked by inhibitors of protein binding (phloretin, bromosulphothalein, 5,5 -di phenylhydan-toin and 8-anilino-1-naphthalene sulphonic acid) and by certain sulphydryl blockers (p-hydroxymercuribenzoate and /V-cthylmaleimide)59,63,64. 

The stability constants of complexes of zirconium with NTA, EDTA, 1,2-diamine-cyclohexanetetraacetic acid, chloride, nitrate and sulphate were determined by an ion exchange method using dinonyl naphthalene sulphonic acid in heptane as the liquid ion exchanger. The experiments were conducted in 2 M HCIO4 and at (20 1)°C. In the chloride and nitrate experiments, the concentration of CT or NO3 was varied to 1.8 M and, as such, a mixed perchlorate-chloride or perchlorate-nitrate medium was used in these experiments, that changed from being perchlorate dominant to being either chloride or nitrate dominant. 

An organic phase containing 0.05 M dinonyl naphthalene sulphonic acid in benzene was used to extract thorium from 2.0 M perchloric and sulphuric acid solutions at 10, 25, or 40°C. The data on values as a function of temperature and molarity of HSO4 are presented. The authors report the values of equilibrium constants as a function of tern-... 

This paper describes a study of the aqueous actinide fluoride complexes. Only the Th(IV) data will be discussed. The experiments have been made at 25°C in a 1.00 M HCIO4 ionic medium. For the Th(IV)-fluoride system two experimental methods were used at different temperatures (1) potentiometiy using a fluoride sensitive electrode (at 3, 25 and 47°C) and (2) liquid-liquid extraction with dinonyl naphthalene sulphonic acid (at 10, 25 and 55°C). The experimental methods are briefly described, with no information on primaiy experimental data. However, the work was done in a specialist laboratory and this review therefore accepts the equilibrium constants proposed as listed in Table A-47. The authors have used the temperature variation of the equilibrium constants to deduce the enthalpy and entropy of reaction, but these quantities are very uncertain due to the experimental errors. These quantities for the reaction between Th" and F calculated using the dissociation constant of HF are given in Table A-46. 

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