As for mostamides, the spectroscopic evidence indicates partial double bond character for the C−N and C−O bonds.Thus, theinfrared spectrum shows a C=O stretching frequency at only 1675 cm−1, whereas a ketone would absorb near 1700 cm−1.[6]
The ambient temperature1H NMR spectrum shows two methyl signals, indicative of hindered rotation about the (O)C−N bond.[6] At temperatures near 100 °C, the 500 MHz NMR spectrum of this compound shows only one signal for the methyl groups.
DMF is miscible with water.[8] The vapour pressure at 20 °C is 3.5 hPa.[9] AHenry's law constant of 7.47 × 10−5 hPa·m3/mol can be deduced from an experimentally determined equilibrium constant at 25 °C.[10] Thepartition coefficient log POW is measured to −0.85.[11] Since the density of DMF (0.95 g·cm−3 at 20 °C[8]) is similar to that of water, significant flotation or stratification in surface waters in case of accidental losses is not expected.
Left: two resonance structures of DMF. Right: illustration highlighting delocalization.
DMF is hydrolyzed by strong acids and bases, especially at elevated temperatures. Withsodium hydroxide, DMF converts to formate and dimethylamine. DMF undergoesdecarbonylation near its boiling point to give dimethylamine. Distillation is therefore conducted under reduced pressure at lower temperatures.[12]
In one of its main uses inorganic synthesis, DMF is a reagent in theVilsmeier–Haack reaction, which is used to formylate aromatic compounds.[13][14] The process involves initial conversion of DMF to a chloroiminium ion, [(CH3)2N=CH(Cl)]+, known as aVilsmeier reagent,[15] which attacks arenes.
Dimethylformamide forms 1:1adducts with a variety of Lewis acids such as the soft acidI2, and the hard acidphenol. It is classified as ahard Lewis base and itsECW model base parameters are EB = 2.19 and CB = 1.31.[17] Its relative donor strength toward a series of acids, versus other Lewis bases, can be illustrated byC-B plots.[18][19]
DMF was first obtained in 1893 by the French chemistAlbert Verley (1867–1959), by distilling a mixture of dimethylamine hydrochloride andpotassium formate.[20]
The primary use of DMF is as a solvent with low evaporation rate. DMF is used in the production ofacrylic fibers andplastics. It is also used as a solvent inpeptide coupling for pharmaceuticals, in the development and production ofpesticides, and in the manufacture ofadhesives, syntheticleathers, fibers, films, and surface coatings.[8]
It is used in the manufacturing of solvent dyes as an important raw material. It is consumed during reaction.
Pureacetylene gas cannot be compressed and stored without the danger of explosion. Industrial acetylene is safely compressed in the presence of dimethylformamide, which forms a safe, concentrated solution. The casing is also filled withagamassan, which renders it safe to transport and use.
As a cheap and common reagent, DMF has many uses in a research laboratory.
DMF-d7 in the presence of a catalytic amount ofpotassiumtert-butoxide under microwave heating is a reagent for deuteration of polyaromatic hydrocarbons.
Dimethylformamide vapor exposure has shown reduced alcohol tolerance and skin irritation in some cases.[30]
On 20 June 2018, theDanish Environmental Protective Agency published an article about DMF's use insquishies. The density of the compound in the toy resulted in all squishies being removed from the Danish market. All squishies were recommended to be thrown out as household waste.[31]
^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.ISBN978-0-85404-182-4.The traditional name 'formamide' is retained for HCO-NH2 and is the preferred IUPAC name. Substitution is permitted on the –NH2 group.
^H. S. Gutowsky; C. H. Holm (1956). "Rate Processes and Nuclear Magnetic Resonance Spectra. II. Hindered Internal Rotation of Amides".J. Chem. Phys.25 (6):1228–1234.Bibcode:1956JChPh..25.1228G.doi:10.1063/1.1743184.
^IPCS (International Programme on Chemical Safety) (1991). Environmental Health Criteria 114 "Dimethylformamide" United Nations Environment Programme, International Labour Organisation, World Health Organization; 1–124.
^abVilsmeier, Anton; Haack, Albrecht (1927). "Über die Einwirkung von Halogenphosphor auf Alkyl-formanilide. Eine neue Methode zur Darstellung sekundärer und tertiärerp-Alkylamino-benzaldehyde" [On the reaction of phosphorus halides with alkyl formanilides. A new method for the preparation of secondary and tertiaryp-alkylamino-benzaldehyde].Ber. Dtsch. Chem. Ges. A/B (in German).60 (1):119–122.doi:10.1002/cber.19270600118.
^Laurence, C. and Gal, J-F. Lewis Basicity and Affinity Scales, Data and Measurement, (Wiley 2010) pp 50-51 ISBN 978-0-470-74957-9
^Cramer, R. E.; Bopp, T. T. (1977). "Graphical display of the enthalpies of adduct formation for Lewis acids and bases".Journal of Chemical Education.54:612–613.doi:10.1021/ed054p612. The plots shown in this paper used older parameters. Improved E&C parameters are listed inECW model.
^Verley, A. (1893)."Sur la préparation des amides en général" [On the preparation of amides in general].Bulletin de la Société Chimique de Paris. 3rd series (in French).9:690–692. On p. 692, Verley states that DMF is prepared by a procedure analogous to that for the preparation of dimethylacetamide (see p. 691), which would be by distilling dimethylamine hydrochloride andpotassium formate.
^Weissermel, K.; Arpe, H.-J. (2003).Industrial Organic Chemistry: Important Raw Materials and Intermediates. Wiley-VCH. pp. 45–46.ISBN3-527-30578-5.
^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.PMID3358569.
