Dimethyl sulfoxide
From Wikipedia, the free encyclopedia
Dimethyl sulfoxide | |
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General | |
Systematic name | Dimethyl sulfoxide |
Other names | Methyl sulfoxide methylsulfinylmethane DMSO |
Molecular formula | C2H6OS |
SMILES | CS(C)=O |
Molar mass | 78.13 g/mol |
Appearance | Clear, colorless liquid |
CAS number | [67-68-5] |
Properties | |
Density and phase | 1.1004 g/cm3, liquid |
Solubility in water | Miscible |
Solubility in ethanol, benzene, chloroform |
Miscible |
Melting point | 18.5 °C (292 K) |
Boiling point | 189 °C (462 K) |
Viscosity | 1.996 cP at 20 °C |
Acid dissociation constant | 35 (in DMSO) |
Structure | |
Dipole moment | 3.96 D |
Hazards | |
MSDS | External MSDS |
Main hazards | Irritant (Xi) |
NFPA 704 | |
R-phrases | R36/37/38 |
S-phrases | S26, S37/39 |
Flash point | 95 °C |
RTECS number | PV6210000 |
Supplementary data page | |
Structure and properties |
n, εr, etc. |
Thermodynamic data |
Phase behaviour Solid, liquid, gas |
Spectral data | UV, IR, NMR, MS |
Related compounds | |
Related sulfoxides | diethyl sulfoxide |
Related compounds | dimethyl sulfide, dimethyl sulfone, acetone |
Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
Dimethyl sulfoxide (DMSO) is the chemical compound (CH3)2SO. This colorless liquid is an important "dipolar aprotic solvent." It is readily miscible in a wide range of organic solvents as well as water. It has a distinctive property of penetrating the skin very readily, allowing the handler to taste it. Some describe it as an "oyster-like" taste, others claim it tastes like garlic.
Contents |
[edit] Production
Dimethyl sulfoxide is a by-product of wood pulping. One of the leading suppliers of DMSO is the Gaylord company in the USA.
[edit] Uses
DMSO is frequently used as solvent in a number of chemical reactions. In particular it is an excellent reaction solvent for SN2 alkylations: it is possible to alkylate indoles with very high yields using potassium hydroxide as the base and a similar reaction also occurs with phenols. DMSO can be reacted with methyl iodide to form a sulfoxonium ion which can be reacted with sodium hydride to form a sulfur ylide. The methyl groups of DMSO are somewhat acidic in character (pKa=35) due to the stabilization of the resultant anions by the sulfoxide group.
DMSO was discovered in 1867, but was not used commercially until after WWII. Other than its use as a solvent, both in organic synthesis and industrial applications (polymer chemistry, pharmaceuticals and agrochemicals), DMSO also makes a very good paint stripper: it is able to remove many paints from both wood and metal in a small amount of time. It is thought to be much safer than many of the other chemicals used as paint strippers, such as nitromethane and dichloromethane.
In organic synthesis, DMSO can also be used in a number of oxidation reactions[1], the Pfitzner-Moffatt oxidation and the Swern oxidation.[2]
DMSO is also employed as a rinsing agent in the electronics industry and, in its deuterated form (DMSO-d6), is a useful solvent in NMR due to its ability to dissolve a wide range of chemical compounds and its minimal interference with the sample signals. In cryobiology DMSO has been used as a cryoprotectant and is still an important constituent of cryoprotectant vitrification mixtures used to preserve organs, tissues, and cell suspensions. It is particularly important in the freezing and long-term storage of embryonic stem cells and hematopoietic stem cell, which are often frozen in a mixture of 10% DMSO and 90% fetal calf serum. As part of an autologous bone marrow transplant the DMSO is re-infused along with the patient's own hematopoietic stem cell.
Use of DMSO in medicine dates from around 1963, when a University of Oregon Medical School team, headed by Stanley Jacob, discovered it could penetrate deeply through the skin and other membranes without damaging them and could carry other compounds deep into a biological system. Some people report an onion- or garlic-like taste after contact with the skin. This is likely due to catabolic processes which reduce DMSO to dimethyl sulfide. In the medical field DMSO is predominantly used as a topical analgesic, a vehicle for topical application of pharmaceuticals, as an anti-inflammatory and an antioxidant. It has been examined for the treatment of an extraordinary number of conditions and ailments. The Food and Drug Administration (FDA) has approved DMSO usage only for the palliative treatment of interstitial cystitis. Also, DMSO is commonly used in the veterinary field as a liniment for horses.
Because DMSO increases the rate of absorption of some compounds through organic tissues including skin, it can be used as a drug delivery system.
Dimethyl sulfoxide is the most powerful readily available organic solvent. It dissolves a great variety of organic substances to the highest loading level, including carbohydrates, polymers, peptides, as well as many inorganic salts and gases. Loading levels of 50-60 wt. % are often observed with DMSO (compared with 10-20 wt. % with typical solvents). Therefore it plays a vital role in sample management and High-throughput screening operations in drug design [3].
In certain conditions, dimethyl sulfoxide can produce an explosive reaction when exposed to acid chlorides.
[edit] Other dipolar aprotic solvents
DMSO is a key dipolar aprotic solvent. It is less toxic than other members of this class: dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, HMPA.
[edit] Safety
DMSO easily penetrates the skin. This means substances dissolved in DMSO may be absorbed very quickly. For instance, a solution of sodium cyanide in DMSO can cause cyanide poisoning through skin contact. DMSO by itself has low toxicity.[4]
DMSO can also irritate the skin; smooth skin is generally more susceptible to DMSO irritation than rough skin.[5]
[edit] See also
- MSM, a related chemical often used as a dietary supplement
[edit] References
- ^ Epstein W.W., Sweat F.W. (1967). "Dimethyl Sulfoxide Oxidations". Chemical Reviews 67: 247-260. DOI:10.1021/cr60247a001.
- ^ Tidwell, T.T. (1990). "Oxidation of Alcohols by Activated Dimethyl Sulfoxide and Related Reactions: An Update". Synthesis: 857-870. DOI:10.1055/s-1990-27036.
- ^ Balakin, K. V., Savchuk, N. P., Tetko I. V. (2006). "In silico approaches to prediction of aqueous and DMSO solubility of drug-like compounds: trends, problems and solutions)". Curr. Med. Chem. 13 (2). DOI:10.2174/092986706775197917.
- ^ Vignes, Robert (August 2000). Dimethyl Sulfoxide (DMSO): A "new" clean, unique, superior solvent, American Chemical Society Annual Meeting
- ^ Experimental Dermatology 1997 Aug;6(4):157-60.
[edit] External links
Urologicals (G04) edit | ||
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Acidifiers: | ||
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Other urologicals: |
Acetohydroxamic acid, Collagen, Dimethyl sulfoxide, Magnesium hydroxide, Phenazopyridine, Phenyl salicylate, Succinimide |
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For benign prostatic hypertrophy: |
5α-reductase inhibitors: Dutasteride, Finasteride |