Dimethyl sulfoxide,CAS 67-68-5

Dimethyl sulfoxide (abbreviated DMSO) is a sulfur-containing organic compound; molecule formula: (CH3) 2SO; It exhibits as colorless, odorless, hygroscopic and flammable transparent liquid at room temperature. It has both high polarity as well as high-boiling point. It also has aprotic and water-miscible characteristics. It has low toxicity, good thermal stability, and is not miscible with paraffin.

Dimethyl sulfoxide Use and Manufacturing
Methods of Manufacturing
Dimethyl sulfoxide is generally produced by dimethyl sulfide oxidation, due to the use of oxidants and oxidation methods are different, and thus have different production processes.
1. Methanol carbon disulfide methanol and carbon disulfide as raw materials, γ-Al2O3 as a catalyst, the first synthesis of dimethyl sulfide, and then with nitrogen dioxide (or nitric acid) oxidation of dimethyl sulfoxide.
2. Hydrogen peroxide to acetone as a buffer medium, so that dimethyl sulfide and hydrogen peroxide reaction. The production of dimethyl sulfoxide with this method is costly and unsuitable for mass production.
3. Nitrogen dioxide method to methanol and hydrogen sulfide in the role of γ-alumina generated dimethyl sulfide; sulfuric acid and sodium nitrite reaction to produce nitrogen dioxide; dimethyl sulfide and nitrogen dioxide in the 60-80 ℃ gas-liquid oxidation reaction to produce crude dimethyl sulfoxide, but also directly with oxygen for oxidation, the same crude dimethyl sulfoxide, and then by vacuum distillation, refined dimethyl sulfoxide finished. This method is more advanced production methods.
4. Dimethyl sulfate method with dimethyl sulfate and sodium sulfide reaction, obtained dimethyl sulfide; sulfuric acid and sodium nitrite reaction to produce nitrogen dioxide; dimethyl sulfide and nitrogen dioxide oxidation of crude dimethyl Thiosulfone, and then neutralized, distilled after the fine dimethyl sulfoxide. In addition, dimethyl sulfoxide was produced from dimethyl sulfide by anodic oxidation. Purification method: After the distillation of dimethylsulfoxide, adding alumina overnight, with high 50cm, filled with ceramic saddle packing distillation column, at 266.6 ~ 399.9Pa, 50 ℃ under vacuum distillation, collecting the middle distillate The Or dimethyl sulfoxide with CaH2 together for a day, vacuum distillation after drying with molecular sieve, in the nitrogen stream and then under vacuum distillation. Can also be refined step by step crystallization.
5. Dimethyl sulfide (prepared by the reaction of dimethyl sulfate with sodium sulfide) and nitrogen dioxide (from sulfuric acid and sodium nitrite reaction) at 60 ~ 80 ℃ for gas-liquid oxidation reaction of dimethyl Base sulfone crude, and then vacuum distillation, the use of molecular sieve dehydration and then vacuum distillation, that was finished dimethyl sulfoxide.
6. With acetone as the buffer medium, add the same amount of dimethyl sulfide and hydrogen peroxide, stirring reaction, to maintain the temperature 20 ℃: the end of the reaction, direct vacuum distillation can be higher purity of dimethyl sulfoxide.