Nitrogen dioxide Dimethyl sulfoxide

Nitrogen dioxide (NO ) reacts with a wide variety of functional groups and it is the reagent of choice for a number of synthetic transformations. For example, the selective oxidation of sulfide to sulfoxide by NO forms the basis for the commercial production of dimethyl sulfoxide (from dimethyl sulfide) via a catalytic procedure (see below).250 Some representative examples of oxidative transformations carried out with NO are presented in Chart 8. 

Dialkyl Ditellurium (Thiourea Dioxide Method)2 A mixture of 128 mg (1.0 mmol) of elemental tellurium, 4 mg (0.01 mmol) of cetyltrimethylammonium bromide, 0.75 ml tetrahydrofuran, and 0.5 ml dimethyl sulfoxide is heated at 80° for 15 min under an atmosphere of deoxygenated nitrogen. To this mixture is added 100 mg (1.0 mmol) of thiourea dioxide, 112 mg (2.6 mmol) sodium hydroxide, and 0.75 ml water. The resulting mixture is refluxed for 1 h. The purple solution is then cooled to 15°. Alkyl halide (2.0 mmol) is added and the mixture is stirred at 20° for 1 h. After normal work-up, the dark-red oils were passed through a pad of Celite with dichloromethane as the mobile phase. 

Properties Yellow powder. D 1.65 (20/20C), mp above 180C (decomposes). Insoluble in common solvents soluble in dimethyl sulfoxide. Hydrolyzes at high temperatures to nitrogen, carbon dioxide, and ammonia. 

After c/5,ds-1,5-cyclooctadiene, b.p. 67°-68°C (46 mm) ( + 99.8% pure VPC), and the distilled solvents are added, the flask is chilled to - 70°C and anhydrous sulfur dioxide, as a liquid, is transferred under nitrogen to the flask. With the flask still at - 70°, the catalyst is added and the reaction mixture allowed to rise to the reflux temperature of the given mixture. The time of reaction noted in Table XI refers to elapsed time from the addition of the catalyst to the precipitation of the reaction mixture. For those mixtures in which such polymer solvents as dimethyl sulfoxide and tetramethylene sulfone are used, the polymer remains in solution and is precipitated by the addition of methanol. For nonsolvents the polymer is precipitated by the addition of methanol. For non-solvents the polymer is precipitated during the polymerization. In all cases, the isolated... 

Cryotherapy with liquid nitrogen or carbon dioxide snow is usually efficacious in very mild infestations, but it must be performed for a fair depth beyond the site of progression apparent at the visible lesion. Good results have also been obtained using topical thiabendazole in 10% suspension or 2% in dimethyl-sulfoxide. In cases characterized by diffuse lesions, oral thiabendazole at doses of 20-50 mg/kg/day for 7-10 days may be used (Stromberg and Christie 1976). 

Actually the irradiation chemistry of even simple amino acids and peptides is much more complex than these equations imply, and many other radiochemical products have been reported (13, 14, 49). These include glyoxylic acid, formaldehyde, hydrogen peroxide, carbon dioxide, succinic acid, aspartic acid, diaminosuccinic acid, methylamine, methane, dimethyl mercaptan, a-aminobutyric acid, methionine sulfoxide, methinonine sul-fone, methionine sulfoxime, homocysteic acid, and several unidentified nitrogen compounds (46, 51). 

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