Sulfonic acid methanesulfonic acid

It is even possible to have a negative charge of an organic acid delocalized over three atoms-as in the anions of the sulfonic acids. Methanesulfonic acid has a p/C , of -1.9. 

ACIDS, ORGANIC Acetyl sulfuric acid. d-(+)-Camphor-10-sulfonic acid. Formic acid. Methanesulfonic acid. Picric acid. p-Tolucnesulfonic acid. Trichloroacetic acid. Trifluoroacetic acid. Trifluorometh-ancsulfonic acid. 

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). 

The choice of catalyst is based primarily on economic effects and product purity requirements. More recentiy, the handling of waste associated with the choice of catalyst has become an important factor in the economic evaluation. Catalysts that produce less waste and more easily handled waste by-products are strongly preferred by alkylphenol producers. Some commonly used catalysts are sulfuric acid, boron trifluoride, aluminum phenoxide, methanesulfonic acid, toluene—xylene sulfonic acid, cationic-exchange resin, acidic clays, and modified zeoHtes. 

Sulfonic acids are such strong acids that in general they can be considered greater than 99% ionized. The piC value for sulfuric acid is —2.8 as compared to the piC values of —1.92, —1.68, and —2.8 for methanesulfonic acid, ethanesulfonic acid, and benzene sulfonic acid, respectively (3). Trifluoromethanesulfonic acid [1493-13-6] has a piC of less than —2.8, making it one of the strongest acids known (4,5). Trifluoromethanesulfonic acid is also one of the most robust sulfonic acids. Heating this material to 350°C causes no thermal breakdown (6). 

Zinc chloride is a Lewis acid catalyst that promotes cellulose esterification. However, because of the large quantities required, this type of catalyst would be uneconomical for commercial use. Other compounds such as titanium alkoxides, eg, tetrabutoxytitanium (80), sulfate salts containing cadmium, aluminum, and ammonium ions (81), sulfamic acid, and ammonium sulfate (82) have been reported as catalysts for cellulose acetate production. In general, they require reaction temperatures above 50°C for complete esterification. Relatively small amounts (<0.5%) of sulfuric acid combined with phosphoric acid (83), sulfonic acids, eg, methanesulfonic, or alkyl phosphites (84) have been reported as good acetylation catalysts, especially at reaction temperatures above 90°C. 

In laboratory preparations, sulfuric acid and hydrochloric acid have classically been used as esterification catalysts. However, formation of alkyl chlorides or dehydration, isomerization, or polymerization side reactions may result. Sulfonic acids, such as benzenesulfonic acid, toluenesulfonic acid, or methanesulfonic acid, are widely used in plant operations because of their less corrosive nature. Phosphoric acid is sometimes employed, but it leads to rather slow reactions. Soluble or supported metal salts minimize side reactions but usually require higher temperatures than strong acids. 

In contrast to phosphorus esters, sulfur esters are usually cleaved at the carbon-oxygen bond with carbon-fluorine bond formation Cleavage of esteri nf methanesulfonic acid, p-toluenesidfonic acid, and especially trifluoromethane-sulfonic acid (tnflic acid) by fluoride ion is the most widely used method for the conversion of hydroxy compounds to fluoro derivatives Potassium fluoride, triethylamine trihydrofluoride, and tetrabutylammonium fluoride are common sources of the fluoride ion For the cleavage of a variety of alkyl mesylates and tosylates with potassium fluoride, polyethylene glycol 400 is a solvent of choice, the yields are limited by solvolysis of the leaving group by the solvent, but this phenomenon is controlled by bulky substituents, either in the sulfonic acid part or in the alcohol part of the ester [42] (equation 29)... 

Sulfonic acids such as methanesulfonic acid and p-toluenesulfonic acid are strong acids, comparable in acidity with sulfuric acid. 

Salts, Methanesulfonate, FNH3+MeS03—, mp 103-05° with decompn CA Registry No 20175-02-4. It is prepd by the reaction of N-fluoroure thane (FNHCOOfit) with methane-sulfonic acid in chlf (Ref 5)... 

The formation of dimethyl sulfide, dimethyl sulfone, and methane (by H-abstraction) observed in these photolyses is thus accounted for. Hydrogen abstraction by the methylsulfinyl radical affords methanesulfenic acid, CH3SOH, a very reactive molecule, which rapidly undergoes a series of secondary reactions to produce the methanesulfonic acid, methyl methanethiolsulfonate (CH3S02SCH3), and dimethyl disulfide which were also observed during these photolyses. 

Pentyl methanesulfonate [7958-20-3] o I n-Bu O — S CH3 O It decomposes vigorously at 185°C. See entry sulfonic acid esters See other sulfur esters c6h14o3s... 

DeBruyn, W. J., Shorter, J. A., Davidovits, P, Worsnop, D. R., Zahniser, M. S., and Kolb, C. E. Uptake of Gas-Phase Sulfur Species Methanesulfonic-Acid, Dimethylsulfoxide, and Dimethyl Sulfone by Aqueous Surfaces, J. Geophys. Res.-A., 99, 16927-16932, 1994. 

Considerable efforts have centered on carrying out the synthesis of polybenzimidazoles at more moderate temperatures. Polymerization of the isophthalic acid or its diphenyl ester have been successfully carried out in polyphosphoric acid or methanesulfonic acid-phosphorous pentoxide at 140-180°C, but the reaction is limited by the very low solubilities (<5%) of the reactants in that solvent. The lower reaction temperature is a consequence of activation of the carboxyl reactant via phosphorylation. Lower reaction temperatures are also achieved in hot molten nonsolvents such as sulfolane and diphenyl sulfone, but the need to remove such solvents by a filtration or solvent extraction is a disadvantage. 

The oxidation of dimethyl sulfide (DMS) to dimethyl sulfoxide (DMSO) and the subsequent oxidation of the latter to methanesulfonic acid (MSA) have been observed in field studies. For example, one study in Antarctica which focused on the chemistry of dimethyl sulfide (Berresheim and Eisele, 1998) measured not only DMS but also a variety of its oxidation products, including DMSO, MSA, and dimethyl sulfone (Berresheim et al., 1998). The measured concentrations of DMSO were in agreement with model results if 80-100% of the OH + DMS reaction gave DMSO as discussed earlier, the addition channel that leads to DMSO becomes relatively more important at the lower temperatures found in Antarctica. Furthermore, the... 

S—OH II R—S—OH II Sulfonic acid CH,—S—OH II Methane sulfonic acid Methanesulfonic... 

Problem 3.30 Why is a sulfonic acid, such as methanesulfonic acid (CH,SO,H), a stronger acid than a selenic acid, such as methaneselenic acid (CH,SeO,H) ... 

CYCLOPENTENONES Boron tritluoride etheratc. Coppcr(I) trifluoromcthyl-sulfonate. 5,5-Dimethoxy-l,2,3,4-tctra-chlorocyclopentadiene. 1-(Dimethyl-amino)-3-pentenotrile. Methanesulfonic acid. Phosphoric acid-formic acid. Tetrakis(lriphenylphosphinc)palladiuni. 

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