Naphthalene sulfonic acid,/!-,

If the released electrophile HSOs+ is not intercepted during the protodesulfonylation as in Figure 5.7, it reacts with the defunctionalized aromatic compound again. In this way an isomer of the original sulfonic acid may be obtained. The best-known example of such an isomerization is the conversion of naphthalene-1-sulfonic acid into naphthalene-2-sulfonic acid (Figure 5.8). Naphthalene-1-sulfonic acid is destabilized by the so-called peri-interaction, that is, the steric interaction between the Cs—H bond of the naphthalene and the substituent on Cl. The peri-interaction is thus a cis-alkene strain. Because naphthalene-2-sulfonic acid does not... 

POPOP p-bis[2-(5-phenyloxazoyl)]benzene. t ANS, anilino-8-naphthalene sulfonic acid. t TNS, 2-p-toluidinylnaphthalene-6-sulfonate. 

Amino-3-hydroxy-7-nitro-l-naphthalene-sulfonic acid [6259-63-8]... 

NaOH solution is added dropwise to an aqueous suspension of this ester at 40—70°C over 1 h and the reaction mixture kept for 2 h to give 86.6% DHNA of 98.7% purity (74), which is then esterified with (CgH O) to obtain PDNA. The esterification process is dramatically improved by adding a small amount of inorganic or organic acid, preferably methanesulfonic acid, benzene sulfonic acid, or naphthalene sulfonic acid subsequent isolation and crystallisation gives a pure product (75). 

There are three main uses for naphthalene sulfonic acid derivatives (75—79) as naphthalenic tanning material alkyl naphthalene sulfonates for industrial appHcations as nondetergent wetting agents and as dye intermediates. Consumption of naphthalene sulfonates as surfactants accounts for a large portion of usage. Naphthalene sulfonate—formaldehyde condensates are also used as concrete additives to enhance flow properties. Demand for naphthalene sulfonates in surfactants and dispersent appHcations, particularly in concrete, was expected to increase into the twenty-first century. Consumption as of 1995 was 16 x 10 kg/yr. 

The material, made by a two-step diazotization of each naphthalenic sulfonic acid derivative, is typically used in the form of the neutralized sodium salt. A similar sulfonic acid-based azo dye (4) which falls into the class of reactive dyes is also shown (76). This compound, made similarly to (3), is used as a blue dyestuff for cotton and wool. 

In more recent times, naphthalene has been used in condensation products from naphthalene sulfonic acids, utili2ing formaldehyde as additives to improve the flow properties of concrete these are referred to as superplastici2ers. Another newer appHcation is the production of diisopropylnaphthalenes. The mutual depression of the melting points in the mixture gives a Hquid which is used as a solvent for dyes in the production of carbonless copy paper. 

As in the nitration of naphthalene, sulfonation gives the 1-substituted naphthalene. However, because the reverse reaction (desulfonation) is appreciably fast at higher temperatures, the thermodynamically controlled product, naphthalene-2-sulfonic acid, can also be obtained. Thus it is possible to obtain either of the two possible isomers of naphthalene sulfonic acid. Under kineticaHy controlled conditions naphthalene-l-sulfonic acid [85-47-2] (82) is obtained thermodynamic control gives naphthalene-2-sulfonic acid [120-18-3] (83). 

Toluidino-2-naphthalene sulfonic acid (TNS reagent) cholesterol [180] phospho- and glycolipids [181] neutral lipids [182]... 

For aqueous cement slurries a copolymer of N-vinylpyrrolidone and a salt of styrenesulfonic acid has been proposed [1585]. A naphthalene sulfonic acid salt condensed with formaldehyde serves as a dispersant. 

The same authors studied the CL of 4,4,-[oxalylbis(trifluoromethylsulfo-nyl)imino]to[4-methylmorphilinium trifluoromethane sulfonate] (METQ) with hydrogen peroxide and a fluorophor in the presence of a, p, y, and heptakis 2,6-di-O-methyl P-cyclodextrin [66], The fluorophors studied were rhodamine B (RH B), 8-aniline-l-naphthalene sulfonic acid (ANS), potassium 2-p-toluidinylnaph-thalene-6-sulfonate (TNS), and fluorescein. It was found that TNS, ANS, and fluorescein show CL intensity enhancement in all cyclodextrins, while the CL of rhodamine B is enhanced in a- and y-cyclodextrin and reduced in P-cyclodextrin medium. The enhancement factors were found in the range of 1.4 for rhodamine B in a-cyclodextrin and 300 for TNS in heptakis 2,6-di-O-methyl P-cyclodextrin. The authors conclude that this enhancement could be attributed to increases in reaction rate, excitation efficiency, and fluorescence efficiency of the emitting species. Inclusion of a reaction intermediate and fluorophore in the cyclodextrin cavity is proposed as one possible mechanism for the observed enhancement. 

The pigments are synthesized by diazotizing the aniline derivative or the aniline sulfonic acid with sodium nitrite in hydrochloric acid and subsequently coupling onto the naphthalene sulfonic acid derivative, which is previously dissolved by neutralizing with a sodium hydroxide solution, producing the corresponding azo dye solution. 

Table 22 shows the monoazo pigment lakes which are based on naphthalene sulfonic acid (CP = coupling position). 

FIGURE 6.16 Separation of 1 = phenol 2 = 2-naphthalene sulfonic acid 3 = p-xylenesulfonic acid 4 = caffeine 5 = nortriptyline 6 = diphenhydramine 7 = benzylamine 8 = procainamide on Atlantis silica column (25 x 0.46 cm, 5 xm particles). Mobile phase acetonitrile-0.1 M ammonium formate pH 3.0 (85 15, v/v), 1 mLmin b... 

Mono(2-ethylhexyl)phosphoric acid Dinonyl naphthalene sulfonic acid w-Octane CX5 1.3 ... 

Finally, a few miscellaneous compounds which were identified in the Delaware River and which have not been previously reported as water contaminants will be discussed Chloro (trifluoromethyl) aniline and chloro (trifluoromethyl) nitrobenzene (no. 55 and 56) were identified in the water, they had maximum concentrations at river mile 78. Both compounds represent common sub-structures in various pesticide and dye molecules, and several of the companies located along the river have patents using these compounds (30-32j. It is possible that these compounds are actually present in the river water as such, but it is also possible that they are formed in the GC injection port by pyrolytic degradation of larger pesticide or dye molecules (see above). All three binaphthyl-sulfone isomers (no. 92) were identified in the river water near Philadelphia. Product literature for one of the companies in the area indicates production of condensed sulfonated polymers derived from naphthalene sulfonic acid and maleic anhydride. It seems likely that the binaphthylsulfones are formed as by-products during preparation of this commercial product. 

Salts of high-molecular-weight condensation product of naphthalene sulfonic acid. 

As one of the probes, fluorescence compounds are known. The fluorescence probe such as 8-anilino-l-naphthalene sulfonic acid ammonium salt(ANS) has been used as an indicator of membrane... 

Quaternary ammonium salts and salts of alkyl naphthalene sulfonic acid were some of the first compounds to be used effectively as fuel demulsifiers and dehazers. Today, a wide range of monomeric and polymeric demulsifiers and dehazers exist. 

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