Methanesulfonic anhydride

Purified by careful fractionation and collecting the middle fraction. Suspected CARCINOGEN. Note that MeS03H has b 134.5-135 , 167-167.5 /10mm and methanesulfonic anhydride has b 138 /10mm)— both are possible impurities. 

Other useful dehydrating agents are dimethylaminosulfur trifluoride (DAST), methyl A -(triethylammoniosulfonyl)carbamate (Burgess salt), acetic anhydride, oxalyl chloride, and phosphorous oxychloride, each one in combination with triethylamine (89). Dehydration of O-sUylated hydroxamic acids using trifluoro-methanesulfonic anhydride and triethylamine under mild conditions also gave nitrile oxides, which in the presence of olefins led to the formation of 2-isoxazolines in moderate to good yields (90). In view of the less readily available starting materials, this method probably will be of limited use. 

Methanesulfonic anhydride Ms20 Briefly mentioned by Swern269 and Albright,268 it delivers from good to excellent yields at —20°C... 

An analogous result was first observed by Thomas <1993S767> and has also been reported elsewhere <2000JME488>. However, in the latter study, the secondary amide was converted into a tetrazole using trifluoro-methanesulfonic anhydride (Tf20) and sodium azide. 

OXIDATIVE LACTONIZATION Dimethyl sulfoxide-Methanesulfonic anhydride. Lead tetraacetate. 

Oxidative laetonization. A recently discovered group of mycotoxins known as tryptoquivalineS has a novel spirolactone unit derived from N-acyltryptophans. A typical member of the group, tryptoquivaline G (1), has now been synthesized by Biichi and co-workers and has been shown to be derived from D-tryptophan. A key step involves oxidation of a derivative (2) of L-tryptophan with DMSO and methanesulfonic anhydride (2 equiv.) to 3 and 4. NBS has been used for such a reaction, but it can also effect undesired nuclear bromination. The main product 3 was converted in several steps into tryptoquivaline L, the C,9 epimer of 1. Contra-thermodynamic epimerization (KH, then protonation) converted this isomer into 1 and thus proved the absolute configuration. 

Methanesulfonic acid, sulfonylation of carbohydrates by, 239 Methanesulfonic anhydride, sulfonylation of carbohydrates by, 238 Methanesulfonyl chloride, sulfonylation agent for sugars, 236... 

NaHCOs, and methanesulfonic anhydride.Dimethyl sulfoxide in 48% HBr oxidizes benzylic alcohols the aryl aldehydes.Note that Swern oxidation of molecules having alcohol moieties, as well as a disulfide, leads to the ketone without oxidation of the sulfur. Sulfoxides other than DMSO can be used in conjunction with oxalyl chloride for the oxidation of alcohols,including fluorinated sulfoxides and a polymer-bound sulfoxide. ... 

Methanesulfonic anhydride (Me2S205) dissolves Sb203 on prolonged heating to form... 

Methanesulfonates of bismuth include [Bi(03SMe)3], prepared from Bi203 and methanesulfonic anhydride. This is converted to [Bi(03SMe)4] by reaction with M[03SMe] (M = Na, NH4, etc.). ... 

Metaphosphoric acid, 665-666 Methacrolein, 467 Methallyl halide, 915, 1040 Methallyl isocyanate, 1172 Methanq>hosphonyl dichloride, 666 Methanesulfonic acid, 458, 666-667,791 Methanesulfonic anhydride, 667 Methanesulfonyl chloride, see Mesyl chloride... 

Acylation (see also Acetylation, Cathylation) Acyl fluorides. Benzoylchloride (see Hippuric acid, preparation). N-Carbonylsulfamic acid chloride. Chloroacetic anhydride. Chloroacetyl chloride. Magnesium. Mesyl chloride. Methanesulfonic anhydride. 1-Morpholinocyclo-hexene. Pyridine. Sodium diisopropylamide. Sodium hydride. Trifluoroacetic anhydride. 

Esterification Alumina. Boron trifluoride. Diazomethane. Dimethylformamide dimethyl acetal. Dimethylformamide dineopentyl acetal. Dimethyl sulfite. Diphenyidiazomethane. Ethyldicyclohexylamine. Ion-exchange resins. Isobutene. Methanesulfonic anhydride. 3 % Methanolic HCl (see Acetyl chloride). Methyl iodide. l-Methyl-3-p-tolyltriazine. Poly-phosphoric acid. Sulfosalicylic acid. Sulfuryl chloride. p-Toluenesulfonic acid. p-Tpluene-sulfonyl chloride. Triethylamine. Triethylorthoformate. Trifluoroacetic anhydride. Esterification of phosphoric acid Trichloroacetonitrile. 

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