Dimethylformamide

Dimethylformamide
Names
Preferred IUPAC name
N,N-Dimethylformamide[1]
Other names
Dimethylformamide
N,N-Dimethylmethanamide[2]
DMF
Identifiers
68-12-2 YesY
3D model (Jmol) Interactive image
3DMet B00545
605365
ChEBI CHEBI:17741 YesY
ChEMBL ChEMBL268291 YesY
ChemSpider 5993 YesY
DrugBank DB01844 YesY
ECHA InfoCard 100.000.617
EC Number 200-679-5
KEGG C03134 YesY
MeSH Dimethylformamide
PubChem 6228
RTECS number LQ2100000
UNII 8696NH0Y2X YesY
UN number 2265
Properties
C3H7NO
Molar mass 73.10 g·mol−1
Appearance Colourless liquid
Odor fishy, ammoniacal
Density 0.948 g mL−1
Melting point −60.5 °C; −76.8 °F; 212.7 K
Boiling point 152 to 154 °C; 305 to 309 °F; 425 to 427 K
Miscible
log P −0.829
Vapor pressure 516 Pa
UV-vismax) 270 nm
Absorbance 1.00
1.4305 (at 20 °C)
Viscosity 0.92 mPa s (at 20 °C)
Structure
3.86 D
Thermochemistry
146.05 J K−1 mol−1
−240.6–−238.2 kJ mol−1
−1.9428–−1.9404 MJ mol−1
Hazards
Safety data sheet See: data page
GHS pictograms
GHS signal word DANGER
H226, H312, H319, H332, H360
P280, P305+351+338, P308+313
T
R-phrases R61, R20/21, R36
S-phrases S53, S45
NFPA 704
Flammability code 2: Must be moderately heated or exposed to relatively high ambient temperature before ignition can occur. Flash point between 38 and 93 °C (100 and 200 °F). E.g., diesel fuel Health code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroform Reactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogen Special hazards (white): no codeNFPA 704 four-colored diamond
2
2
0
Flash point 58 °C (136 °F; 331 K)
445 °C (833 °F; 718 K)
Explosive limits 2.2–15.2%
30 mg m−3 (TWA)
Lethal dose or concentration (LD, LC):
  • 1.5 g kg−1 (dermal, rabbit)
  • 2.8 g kg−1 (oral, rat)
  • 3.7 g/kg (mouse, oral)
  • 3.5 g/kg (rat, oral)
3092 ppm (mouse, 2 hr)[3]
5000 ppm (rat, 6 hr)[3]
US health exposure limits (NIOSH):
PEL (Permissible)
TWA 10 ppm (30 mg/m3) [skin][4]
REL (Recommended)
TWA 10 ppm (30 mg/m3) [skin][4]
IDLH (Immediate danger)
500 ppm[4]
Related compounds
Related alkanamides
Related compounds
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Thermodynamic
data
Phase behaviour
solidliquidgas
UV, IR, NMR, MS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY verify (what is YesYN ?)
Infobox references

Dimethylformamide is an organic compound with the formula (CH3)2NC(O)H. Commonly abbreviated as DMF (although this acronym is sometimes used for dimethylfuran, or dimethyl fumarate), this colourless liquid is miscible with water and the majority of organic liquids. DMF is a common solvent for chemical reactions. Dimethylformamide is odorless whereas technical grade or degraded samples often have a fishy smell due to impurity of dimethylamine. As its name indicates, it is a derivative of formamide, the amide of formic acid. DMF is a polar (hydrophilic) aprotic solvent with a high boiling point. It facilitates reactions that follow polar mechanisms, such as SN2 reactions.

Structure and properties

As for most amides, the spectroscopic evidence indicates partial double bond character for the C-N and C-O bonds. Thus, the infrared spectrum shows a C=O stretching frequency at only 1675 cm−1, whereas a ketone would absorb near 1700 cm−1.[5] The methyl groups are inequivalent on the NMR time scale, giving rise to two singlets of 3 protons each at δ 2.97 and 2.88 in the proton NMR spectrum in chloroform-d.[5]

DMF is miscible with water.[6] The vapour pressure at 20 °C is 3.5hPa.[7] 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.[8] The partition coefficient logPOW is measured to −0.85.[9] Since the density of DMF (0.95 g/cm3 at 20 °C[6]) is very similar to that of water, significant flotation or stratification in surface waters in case of accidental losses is not expected.

The two resonance forms of DMF

Reactions

DMF is hydrolyzed by strong acids and bases, especially at elevated temperatures. With sodium hydroxide, DMF converts to formate and dimethylamine. DMF undergoes decarbonylation near its boiling point to give dimethylamine. Distillation is therefore conducted under reduced pressure at lower temperatures.[10]

In one of its main uses in organic synthesis, DMF is a reagent in the Vilsmeier-Haack reaction, which is used to formylate aromatic compounds. The process involves initial conversion of DMF to N,N-dimethyliminium chloride, (CH3)2N=C(Cl)H+, which attacks arenes.

Organolithium compounds react with DMF to give, after hydrolysis, aldehydes.

Production

DMF is prepared by combining methyl formate and dimethylamine or by reaction of dimethylamine with carbon monoxide.[11]

Although currently impractical, DMF can be prepared from supercritical carbon dioxide using ruthenium-based catalysts.[12]

Applications

The primary use of DMF is as a solvent with low evaporation rate. DMF 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.[6]

Niche uses

As a common and cheap reagent, DMF has many uses in the research laboratory.

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.[16]

Toxicity

The potential toxicity of DMF has received considerable attention.[17] It is not classified as human carcinogen (A4), but it is thought to cause birth defects.[18] 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 not classified as to its carcinogenicity to humans,[19] and the United States Environmental Protection Agency does not consider it a cancer risk.

References

  1. Nomenclature of Organic Chemistry : IUPAC Recommendations and Preferred Names 2013 (Blue Book). Cambridge: The Royal Society of Chemistry. 2014. pp. 841, 844. doi:10.1039/9781849733069-FP001. ISBN 978-0-85404-182-4. The traditional name ‘formamide’ is retained for HCO-NH2 and is the preferred IUPAC name. Substitution is permitted on the –NH2 group.
  2. N,N-Dimethylmethanamide, NIST web thermo tables
  3. 1 2 "Dimethylformamide". Immediately Dangerous to Life and Health. National Institute for Occupational Safety and Health (NIOSH).
  4. 1 2 3 "NIOSH Pocket Guide to Chemical Hazards #0226". National Institute for Occupational Safety and Health (NIOSH).
  5. 1 2 "Dimethylformamide". Spectral Database for Organic Compounds. Japan: AIST. Retrieved 2012-06-28.
  6. 1 2 3 Bipp, H.; Kieczka, H. (2005), "Formamides", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a12_001.pub2
  7. IPCS (International Programme on Chemical Safety) (1991). Environmental Health Criteria 114 “Dimethylformamide” United Nations Environment Programme, International Labour Organisation, World Health Organization; 1–124.
  8. Taft, R. W.; Abraham, M. H.; Doherty, R. M.; Kamlet, M. J. (1985). "The molecular properties governing solubilities of organic nonelectrolytes in water". Nature. 313 (6001): 384–386. doi:10.1038/313384a0.
  9. (BASF AG, department of analytical, unpublished data, J-No. 124659/08, 27.11.1987)
  10. Comins, Daniel L.; Joseph, Sajan P. (2001-01-01). Encyclopedia of Reagents for Organic Synthesis. John Wiley & Sons, Ltd. doi:10.1002/047084289x.rd335/abstract. ISBN 9780470842898.
  11. Weissermel, K.; Arpe, H.-J. Industrial Organic Chemistry: Important Raw Materials and Intermediates. Wiley-VCH. pp. 45–46. ISBN 3-527-30578-5.
  12. Walter Leitner; Philip G. Jessop (1999). Chemical synthesis using supercritical fluids. Wiley-VCH. pp. 408–. ISBN 978-3-527-29605-7. Retrieved 27 June 2011.
  13. Clayden, J. (2001). Organic Chemistry. Oxford: Oxford University Press. pp. 276–296. ISBN 0-19-850346-6.
  14. Ansell, M. F. in "The Chemistry of Acyl Halides"; S. Patai, Ed.; John Wiley and Sons: London, 1972; pp 35–68.
  15. Haddon, R.; Itkis, M. (March 2008). "3. Near-Infrared (NIR) Spectroscopy". In Freiman, S.; Hooker, S.; Migler; K.; Arepalli, S. Publication 960-19 Measurement Issues in Single Wall Carbon Nanotubes (pdf). NIST. p. 20. Retrieved 2012-06-28.
  16. UK Chemical Reaction Hazards Forum and references cited therein
  17. Redlich, C.; Beckett, W. S.; Sparer, J.; Barwick, K. W.; Riely, C. A.; Miller, H.; Sigal, S. L.; Shalat, S. L.; Cullen, M. R. (1988). "Liver disease associated with occupational exposure to the solvent dimethylformamide". Annals of Internal Medicine. 108 (5): 680–686. doi:10.7326/0003-4819-108-5-680. PMID 3358569.
  18. Hazardous substance fact sheet for Dimethylformamide
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