Dimethylformamide
From Wikipedia, the free encyclopedia
| Dimethylformamide | |
|---|---|
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| General | |
| Systematic name | N,N-dimethylmethanamide |
| Other names | DMF, dimethylformide, N,N-dimethylformide, DMFA |
| Molecular formula | C3H7NO |
| SMILES | O=CN(C)C |
| Molar mass | 73.09 g/mol |
| Appearance | Clear liquid |
| CAS number | 68-12-2 |
| Properties | |
| Density and phase | 0.944 g/cm³, liquid |
| Solubility in water | Miscible |
| Melting point | -61 °C (212 K) |
| Boiling point | 153 °C (426 K) |
| Acidity (pKa) | ? |
| Basicity (pKb) | ? |
| Viscosity | ? cP at ? °C |
| Structure | |
| Dipole moment | ? D |
| Dielectric Constant | 36.70 |
| Polarity Index | 6.4 |
| Hazards | |
| MSDS | ScienceLab.com |
| Main hazards | ? |
| NFPA 704 |
2
1
0
|
| Flash point | 58 °C |
| Auto-ignition temperature |
445 °C |
| R/S statement | R: 61-20/21-36 S: 53-45 |
| RTECS number | ? |
| 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 amides | Acetamide, Formamide |
| Related compounds | ? |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
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Dimethylformamide (DMF, N,N-dimethylformamide) is a clear liquid, miscible with water and majority of organic solvents. It is a common solvent that is often used in chemical reactions. Pure dimethylformamide is odorless while technical grade or degraded dimethylformamide often has a fishy smell due to dimethylamine impurities. Its name is derived from the fact that it is formamide (the amide of formic acid) with two methyl group substitutions, both of them on the N (nitrogen) atom.
Dimethylformamide is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates the SN2 reaction mechanism. Dimethylformamide is synthesized from formic acid and dimethylamine. Dimethylformamide is not stable in the presence of strong bases like sodium hydroxide or strong acids like hydrochloric acid or sulfuric acid and is hydrolyzed back into formic acid and dimethylamine, especially at elevated temperatures.
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[edit] Chemistry
Due to the contribution of the two possible resonance structures of an amide, the bond order of the carbonyl C=O bond is reduced, while that of the carbon-nitrogen bond is increased. Thus the infrared spectrum of DMF shows a lower C=O stretching frequency at 1675 cm-1[1] than an unsubstuted C=O bond. Also, because of the partial double bond character, the rotation about the C-N axis is slow, making the two methyl groups inequivalent on the NMR time scale, giving rise to two singlets of 3 protons each at \delta; 2.97 and 2.88,[1] instead of one singlet of 6 protons in the proton NMR spectrum.
[edit] Applications
The primary use of dimethylformamide is as a solvent with low evaporation rate. Dimethylformamide is used in the production of acrylic fibers and plastics. It is also used as a solvent in peptide coupling for pharmaceuticals, in the development and production of pesticides, and in the manufacture of adhesives, synthetic leathers, fibers, films, and surface coatings.[2]
It is used as a reagent in the Bouveault aldehyde synthesis and in the Vilsmeier-Haack reaction, another useful method of forming aldehydes.
DMF penetrates most plastics and makes them swell. It therefore frequently occurs as a component of paint strippers.
[edit] Production
Dimethyl formamide is produced with catalyzed reaction of dimethyl amine and carbon monoxide at low pressure and temperature.
[edit] Precautions
Reaction with sodium hydride in DMF as a solvent are somewhat hazardous; exothermic decomposition has been reported at temperatures as low as 26 °C. On a laboratory scale any thermal runaway is (usually) quickly noticed and brought under control with an ice bath and this remains a popular combination of reagents. On a pilot plant scale, on the other hand, several accidents have been reported.
[edit] Toxicity
DMF has been linked to cancer in humans, and it is thought to cause birth defects. In some sectors of industry women are banned from working with DMF. For many reactions, it can be replaced with dimethyl sulfoxide. Most manufacturers of DMF list (Life) or (Chronic) as a health hazard in their MSDS since DMF is not readily disposed of by the body.
According to IARC, DMF may be a possible carcinogen, though EPA does not consider it a cancer risk.
[edit] References
- ^ a b Spectral Database for Organic Compounds, Dimethylformamide, accessed 27 Jan 2007.
- ^ Redlich, C; Beckett, W. S.; Sparer, J.; Barwick, K. W.; Riely, C. A.; Miller, H.; Sigal, S. L.; Shalat, S. L.; and Cullen, M. R.; 1988. Liver disease associated with occupational exposure to the solvent dimethylformamide. Ann. Intern. Med. 108:680-686. PMID 3358569
[edit] External links
- Dimethylformamide usage on Organic Syntheses
- Concise International Chemical Assessment Document 31: N,N-Dimethylformamide
- Material Safety Data Sheet for DMF
- DMF Chronic Toxicity Summary (PDF)
