Acidity continued methanesulfonic acid

A 0.61 N solution (90 cc) of 1-chloro-2-methyl-3-dimethylaminopropane in xylene is then added over 50 minutes and heating with reflux is continued for 20 hours. After cooling, the mixture is treated with water (40 cc) and N methanesulfonic acid (70 cc). The aqueous layer is washed with ether, treated with aqueous sodium hydroxide (density = 1.33 ... 

Reactions of Phosphines. - 1.2.1 Nucleophilic Attack at Carbon. Treatment of the unsaturated y-lactone (177) with tributylphosphine results in selective relacement of chlorine to form the phosphonium salt (178). Reactions of phosphines with alkynes have continued to attract interest. A palladium-catalysed addition of triphenylphosphine to unactivated terminal alkynes in the presence of methanesulfonic acid provides a route to the vinylphosphonium salts (179). This reaction fails with methyldiphenylphos-... 

Methanesulfonic acid is primarily manufactured by the batch or continuous oxidation of the methyl mercaptan or dimethyl disulfide with chlorine in saturated aqueous hydrochloric acidJ This chemistry is also the basis for much of the worldwide production of MSC, with photochlorination of methane (vide infra) being the most significant commercial alternative. Other alkanesulfonyl chlorides and sulfonic acids have also been produced in lesser quantities by the CI2/H2O oxidation. Reaction yields are typically 92-100%. The HCl by-product separates as vapor from the saturated reaction mixture. It is absorbed into water to afford a... 

Methanesulfonic acid 2 b (92 mg, 0.96 mmol) and (diacetoxyiodo)benzene 1 a (302 mg, 0.94 mmol) were placed in an agate mortar and intensively ground. The formation of acetic acid was observed and the reaction mass turned yellow. After approximately 1 min the color of the reaction mixture changed to white and the formation of white crystals was observed. The grinding was continued for... 

The use of electricity in reactions is clean and, at least in some cases, can produce no waste. Toxic heavy metal ions need not be involved in the reaction. Hazardous or expensive reagents, if needed, can be generated in situ where contact with them will not occur. The actual oxidant is used in catalytic amounts, with its reduced form being reoxidized continuously by the electricity. In this way, 1 mol% of ruthenium(III) chloride can be used in aqueous sodium chloride to oxidize benzyl alcohol to benzaldehyde at 25°C in 80% yield. The benzaldehyde can, in turn, be oxidized to benzoic acid by the same system in 90% yield.289 The actual oxidant is ruthenium tetroxide. Naphthalene can be oxidized to naphthoquinone with 98% selectivity using a small amount of cerium salt in aqueous methanesulfonic acid when the cerium(III) that forms is reoxidized to cerium(IV) electrically.290 Substituted aromatic compounds can be oxidized to the corresponding phenols electrically with a platinum electrode in trifluoroacetic acid, tri-ethylamine, and methylene chloride.291 With ethyl benzoate, the product is a mixture of 44 34 22 o/m/fhhy-... 

FIGURE 4. Absorptivity of the continuous absorption at 1400 cm -1 in the systems methanesulfonic acid + various oxygen bases in CD3CN, plotted as a function of ApKa. The numbers correspond to the number of the base in Table 7. Reprinted with permission from Boner and Zundel, J. Phys. Chem., 89, 1408. Copyright (1985) American Chemical Society... 

Dionex offers a just add water system for electrolyte generation and purification of commonly used eluents such as KOH and methanesulfonic acid. Eluents are generated from deionized water using an Eluent Generator (EG) cartridge and then polished of contaminants using a continuous-regeneration trap column. 

In 2001, a third type of suppressor -Atlas Electrolytic Suppressor (AES) - was introduced. The Atlas suppressor is a continuously regenerated suppressor operated in the recycle mode and designed for optimal performance with conventional methanesulfonic acid (MSA) eluents. Able to suppress up to 25mmol/L... 

A quality feature of all cation exchangers suitable for simultaneous analysis of mono- and di-valent cations is the maximal concentration ratio between sodium and ammonium that allows a separation of both components. Under isocratic conditions with 10 mmol/L methanesulfonic acid at 2 mL/min, the lonPac CS12 separates ammonium in the presence of a 250-fold to 500-fold amount of sodium. Higher concentration differences are only applicable when using a step gradient or a continuous concentration gradient (see Section 4.7). 

Nickel peroxide, which is readily obtainable, has proved to be a useful oxidation agent Permanganate oxidation is an effective general method for the conversion of aliphatic nitro into oxo compounds a,/3-Ethyleneketones as well as 1,4-naphthoquinones can be cheaply and safely epoxidized with hypochlorite A rapid direct preparation of peroxy acids in methanesulfonic acid has been published An efficient method for the oxidative removal of the methyl group in position 19 of steroids has been described The application of hydride transfer for carboxylations has been continued. 

---