Dimethyl sulphoxide-triethylamine

The oxidation of primary or secondary alcohols to aldehydes or ketones respectively with dimethyl sulphoxide activated by oxalyl chloride has wide applicability (Swern oxidation).243b The initial reaction between the acid chloride and dimethyl sulphoxide in dichloromethane solvent is vigorous and exothermic at — 60 °C and results in the formation of the complex (7) this complex spontaneously decomposes, even at this low temperature, releasing carbon dioxide and carbon monoxide to form the complex (8). The alcohol is added within 5 minutes, followed after 15 minutes by triethylamine. After a further 5 minutes at low temperature the reaction mixture is allowed to warm to room temperature and work-up follows standard procedures. The ratio of reactants is dimethyl sulphoxide oxalyl chloride alcohol triethylamine 2.2 1.1 1.0 5. 

Azide ions react with 2,4,6-trinitroanisole at temperatures below —10° in aprotic solvents to give an addition complex (Caveng and Zollinger, 1967). The NMR spectrum indicates addition at Cl. Similarly it has been found from NMR evidence (Servis, 1967) that diethyl-amine and triethylamine give adducts at Cl with 2,4,6-trinitroanisole in dimethyl sulphoxide. The latter adduct is unusual in that it is apparently the zwitterion 11. However, addition of triethylamine to... 

Quinoxaline-thiones (144) have been prepared by heating 1,2-diamino-benzene with a-halo-ketones (RCOCH2X), sulphur, and triethylamine in dimethyl sulphoxide. ... 

The reagent was prepared by treating thionyl chloride dropwise in dichloromethane at -60° under nitrogen with dimethyl sulphoxide in dichloromethane. After stirring (20 mins.), phenol in dichloromethane was added at -50°, stirring continued for 40 mins, (at -50°), triethylamine in CHjClj added dropwise at -50° to -40°, mixture allowed to reach ambient temp, and poured into IM HCl. 

Oximes as well as amides (p. 249) are converted into nitriles by some silicon derivatives. Hexamethylcyclotrisilazane (8) when heated at 210° for 6 hr with benzaldoxime gives benzonitrile in 72% yield [35]. Carbodiimides in pyridine have a similar action on amides [48]. By replacing pyridine by triethylamine and either ether or carbon tetrachloride, and addition of acetyl or phenacetyl chloride, aldoximes may be converted to nitriles at low temperature [62] examples are PhCN (86.6%), PhCH = CH.CN, (81.4%) and 2-cyanofuran (82.6%). A car-bodi-imide, trifluoroacetic acid and dimethyl sulphoxide (DMSO) mixture has been shown to dehydrate 4-bromobenzaldoxime [63]. 

Mattingley, B. I. Handa, Y. P. Fenby, D. V. Aromatic fluorocarbon mixtures. 7. Excess enthalpies of hexafluotobenzene + triethylamine, + acetone, + diethyl ether, and + dimethyl sulphoxide J. Chem. Thermodyn. 1975, 7,169-173... 

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