Arenesulfonate Salts

A variety of substituted naphthalenes and anthraquinones, bearing one or more sulfonate salt groups, have been investigated by FAB, FD and electrodynamic ionization techniques. The interest in these compounds originated from their important role as dye intermediates. The FD mass spectra of compounds 9a, 18, 2011 and 17,19, 21 and 2212, among other arenesulfonate salts, have been described. Their main features were similar to those of benzene- and alkylbenzenesulfonate salts, with [M + Cat] + usually being the base 

The superiority of the negative-ion mode was also clear from the FD mass spectra of 9a and 17 and of the potassium salts of benzenesulfonic acid, 1-methylphenanthrenesulfonic acid and perylenesulfonic acid13,29, where the unclustered anions were the only significant species desorbed from the respective salts, dissolved in a polyethylene oxide matrix. Only weak negative-ion signals could be obtained from the application of electrodynamic ionization mass spectrometry to the disodium salts of 2-naphthol-3,6-disulfonic acid (24a) and of 4,5-dihydroxy-2,7-naphthalenedisulfonic acid (24b)30. 

Transform ICR. Double resonance experiments established a link between the [N02]-ion and [M + O — Cl]- product ion for the corresponding process in the case of 2,6-dinitrochlorobenzene. 

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Fig. 14. Assembly (57) and covalent linkage (63) of 2D net formed by guanidinium alkanesul-fonate (arenesulfonate) salts...

Reaction conditions depend on the reactants and usually involve acid or base catalysis. Examples of X include sulfate, acid sulfate, alkane- or arenesulfonate, chloride, bromide, hydroxyl, alkoxide, perchlorate, etc. RX can also be an alkyl orthoformate or alkyl carboxylate. The reaction of cycHc alkylating agents, eg, epoxides and a2iridines, with sodium or potassium salts of alkyl hydroperoxides also promotes formation of dialkyl peroxides (44,66). Olefinic alkylating agents include acycHc and cycHc olefinic hydrocarbons, vinyl and isopropenyl ethers, enamines, A[-vinylamides, vinyl sulfonates, divinyl sulfone, and a, P-unsaturated compounds, eg, methyl acrylate, mesityl oxide, acrylamide, and acrylonitrile (44,66). 

The cleavage products of several sulfonates are utilized on an industrial scale (Fig. 3). The fusion of aromatic sulfonates with sodium hydroxide [1310-73-2J and other caustic alkalies produces phenohc salts (see Alkylphenols Phenol). Chlorinated aromatics are produced by treatment of an aromatic sulfonate with hydrochloric acid and sodium chlorate [7775-09-9J. Nitriles (qv) (see Supplement) can be produced by reaction of a sulfonate with a cyanide salt. Arenesulfonates can be converted to amines with the use of ammonia. This transformation is also rather facile using mono- and dialkylamines. 

Where X is Br or Q, the free acids may be obtained by acidification of the alkaline solution, but where X is I, the acids must be isolated as salts to avoid reduction of the arsonic acids by HI. Rather than using alkyl haUdes, alkyl or dialkyl sulfates or alkyl arenesulfonates can be used. Primary alkyl haUdes react rapidly and smoothly, secondary haUdes react only slowly, whereas tertiary haUdes do not give arsonic acids. AHyl haUdes undergo the Meyer reaction, but vinyl hahdes do not. Substituted alkyl haUdes can be used eg, ethylene chlorohydrin gives 2-hydroxyethylarsonic acid [65423-87-2], C2H2ASO4. Arsinic acids, R2AsO(OH), are also readily prepared by substituting an alkaU metal arsonite, RAs(OM)2, for sodium arsenite ... 

Salts of diazonium ions with certain arenesulfonate ions also have a relatively high stability in the solid state. They are also used for inhibiting the decomposition of diazonium ions in solution. The most recent experimental data (Roller and Zollinger, 1970 Kampar et al., 1977) point to the formation of molecular complexes of the diazonium ions with the arenesulfonates rather than to diazosulfonates (ArN2 —0S02Ar ) as previously thought. For a diazonium ion in acetic acid/water (4 1) solutions of naphthalene derivatives, the complex equilibrium constants are found to increase in the order naphthalene < 1-methylnaphthalene < naphthalene-1-sulfonic acid < 1-naphthylmethanesulfonic acid. The sequence reflects the combined effects of the electron donor properties of these compounds and the Coulomb attraction between the diazonium cation and the sulfonate anions (where present). Arenediazonium salt solutions are also stabilized by crown ethers (see Sec. 11.2). 

Salts of diazonium ions with certain arenesulfonate ions also have a relatively high stability in the solid state. They are also used for inhibiting the decomposition of diazonium ions in solution. Experimental data42,43 point to the formation of molecular... 

The sulfonate salts of the --deficient heterocycles will undergo many reactions typical of arenesulfonates, such as displacement by hydroxide, on fusion with alkali (e.g. Scheme 129), or by cyanide on fusion with potassium or sodium cyanide. Also, the sulfonation of pyridine is reversible when pyridine-3-sulfonic acid is heated with 100% sulfuric acid and mercury(II) sulfate at approximately 330 °C a mixture is obtained containing mainly pyridine (58RTC963). 

Diaryl tellurium benzenesulfonimide and 1,4-dihydroxybenzene reacted in dry chloroform to give diaryl 2,5-dihydroxyphenyl telluronium salts. With diphenyl tellurium arenesulfon-imides a diphenyl tellurium phenoxide was also isolated3. 

FI. Kimoto, K. Saigo, Y. Ohashi, M. Flasegawa, Molecular recognition in the formation of conglomerate crystal. 2. The role of arenesulfonic acid in the conglomerate crystals of amino acid salts. Bull. Chem. Soc. Jap. 62 (1989) 2189-2195. 

The first reported chemical cleavage of 1,2,4-triazoles subjected to the Schotten-Baumann reaction has been refuted. However, 4-benzylaminotriazolyl arenesulfonates are easily cleaved thanks to the loss of aromaticity in the triazolium salt (63JOC543). Another method is quaternization followed by treatment with concentrated alkali [Pg.745]

Effectiveness as a base [1, 1268, after line 2]. In studying the acetolysis of ethyl arenesulfonates, Bartlett and co-workers2311 wished to add a base sufficiently strong to convert the sulfonic acid produced into an inert sulfonate salt but one that is non-nucleophilic and not able to effect direct displacement (which can happen with sodium or potassium acetate). For this purpose they used urea successfully. 

Sulfuric and hydrochloric acid are the usual catalysts for esterification, but phosphoric and arenesulfonic acids, acid salts, and acid cation-exchangers are also used. Mineral acids act not merely as catalysts but also have waterbinding properties so they are generally used in greater than catalytic amounts, usually 5-10%. 

Arenesulfonic acids and organic bases often form salts that crystallize readily and have sharp melting points, so that these can be used for identification of the acid.117 Forster and Keyworth,118 for example, describe a process for separating the different naphthalenesulfonic acids by way of their ary-lamine salts. Benzidine and bianisidine salts are also mostly sparingly soluble and can be used for separation and quantitative determination of sulfonic acid mixtures.119... 

Toluldine arenemonosulfonates can be prepared by the following general procedure 120 Solutions of equivalent amounts of the potassium arenesulfonate and of /7-toluidine hydrochloride in the minimal amounts of water at 60° are thoroughly mixed under rapid cooling. The /7-toluidine salt is filtered off, washed with a little ice-water, and recrystallized from water, if necessary with addition of charcoal. 

Aromatic phosphines that are difficult to obtain by other methods can be prepared by heating alkali phosphides with arenesulfonic acid salts, best in ethylene glycol ethers ... 

Martin and Figuly have found that the lithium salt of aromatic sulfonic acids facilitates the ort/io-metallation21. When the lithium salt (1) is treated with 1.1 equivalent of BuLi in THF at 0 °C, the ort/io-lithiation is complete in 10 min (equation 4). The dilithiated reagent 2 can be stored at — 20 °C for several weeks without appreciable decomposition, and its reactions with electrophiles give a variety of ort/io-substituted arenesulfonic acids. Desulfurization of 6 with HgS04 in sulfuric acid provides the meta-substituted aromatic derivative (7) that might be otherwise very difficult to obtain (equation 5). 

Although it is reasonable to believe that micelles in water are close to spherical at low surfactant concentrations, e.g., within an order of magnitude of the critical micelle concentration, there is evidence for micellar growth with increasing surfactant or electrolyte concentration. Such growth cannot easily be accommodated to a strictly spherical structure for the micelle, but requires it to become spheroidal. Solutions of some surfactants become very viscous on addition of salts. For example, addition of iodide, arenesulfonate or aromatic carboxylate ion to cationic surfactants sharply increases solution viscosity, suggesting that long, rod-like micelles are formed. 

The special salt effect is another factor that requires at least two ion-pair intermediates to be adequately explained. Addition of salts typically causes an increase in the rate of solvolysis of secondary alkyl arenesulfonates that is linear with salt concentration. The effect of added lithium perchlorate is anomalous toward certain substrates in producing an initial sharp increase in the solvolysis rate, followed by the expected linear increase at higher lithium perchlorate concentrations. Winstein ascribed this to interaction of lithium perchlorate with the solvent-separated ion pair to form a solvent-separated carbonium ion perchlorate ion pair that does not undergo return to the intimate ion pair or covalent substrate. This new ion pair can go on only to product, and its formation leads to an increase in solvolysis rate more pronounced than for a simple medium effect. 

Aryldiazonium salts are more stable than alkyldiazonium salts, which usually react by substitution or elimination under the conditions of their generation. Marked differences are often observed in the pattern of reactivity exhibited by diazonium salt decomposition compared with that seen in solvolysis reactions of the corresponding alkyl halides or arenesulfonates. ... 

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