Dimethylformamide

Dimethylformamide is the organic compound with the formula (CH3)2NC(O)H. Commonly abbreviated DMF (though this acronym is sometimes used for dimethylfuran), this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Pure dimethylformamide is odorless whereas technical grade or degraded dimethylformamide often has a fishy smell due to impurity of dimethylamine. Its name is derived from the fact that it is a derivative of formamide, the amide of formic acid.

Dimethylformamide is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as SN2 reactions. Dimethylformamide can be synthesized from methyl formate and dimethylamine or by reaction of dimethylamine with carbon monoxide. Dimethylformamide is not stable in the presence of strong bases like sodium hydroxide or strong acids such as hydrochloric acid or sulfuric acid and is hydrolyzed back into formic acid and dimethylamine, especially at elevated temperatures.

Structure and properties
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 than an unsubstituted C=O bond. Also, because of the partial double bond character, the rotation about the C-N axis is slow at room temperature, making the two methyl groups inequivalent on the NMR time scale, giving rise to two singlets of 3 protons each at δ 2.97 and 2.88, instead of one singlet of 6 protons in the proton NMR spectrum.

N,N-Dimethylformamide (DMF) is miscible with water in all proportions. The vapour pressure at 20°C is 3.5hPa. A Henry's law constant of 7.47×10−5 hPa·m3/mol can be deduced from an experimentally determined equilibrium constant at 25 °C. The partition coefficient logPOW	is measured to –0.85. Since the density of DMF (0.95 g/cm3 at 20 °C ) is very similar to that of water, significant flotation or stratification in surface waters in case of accidental losses is not expected.



Production
Dimethyl formamide is produced either with catalyzed reaction of dimethylamine and carbon monoxide in methanol  or  the reaction of methyl formate  with dimethylamine. It may also be prepared on a laboratory scale by reacting dimethylamine with formic acid.

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.


 * It is used as a reagent in the Bouveault aldehyde synthesis and in the Vilsmeier-Haack reaction, another useful method of forming aldehydes.
 * It is also a common catalyst used in the synthesis of acyl halides, in particular the synthesis of acyl chlorides from carboxylic acids using oxalyl or thionyl chloride.
 * DMF penetrates most plastics and makes them swell. This property makes it very suitable for solid phase peptide synthesis. It also frequently occurs as a component of paint strippers for this purpose.
 * DMF is very effective at separating and suspending carbon nanotubes, and is recommended by the NIST for use in near infrared spectroscopy of such.
 * DMF is used as a solvent to recover olefins such as 1,3-butadiene via extractive distillation.
 * It is also used in the manufacturing of solvent dyes as an important raw material. It is consumed during reaction.
 * Pure acetylene gas cannot be compressed and stored without the danger of explosion. Industrial acetylene gas is therefore dissolved in dimethylformamide and stored in metal cylinders or bottles. The casing is also filled with agamassan, which renders it safe to transport and use.

Safety
Reactions including the use of sodium hydride in DMF as a solvent are somewhat hazardous; exothermic decompositions have 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.

Toxicity
DMF has been linked to cancer in humans, and it is thought to cause birth defects (refs??). 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 is a possible carcinogen, although EPA does not consider it a cancer risk.