Dimethylacetamide

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Dimethylacetamide
Skeletal formula of dimethylacetamide
Ball and stick model of dimethylacetamide
Identifiers
Abbreviations DMAc[2]
CAS number 127-19-5 YesY
PubChem 31374
ChemSpider 29107 YesY
UNII JCV5VDB3HY YesY
EC number 204-826-4
MeSH dimethylacetamide
ChEMBL CHEMBL11873 YesY
RTECS number AB7700000
Beilstein Reference 1737614
Jmol-3D images Image 1
Image 2
Properties
Molecular formula C4H9NO
Molar mass 87.12 g mol−1
Appearance Colorless liquid
Odor Ammoniacal
Density 0.937 g mL−1
Melting point −20 °C (−4 °F; 253 K)
Boiling point 165.1 °C; 329.1 °F; 438.2 K
Solubility in water Miscible
log P −0.253
Vapor pressure 300 Pa
λmax 270 nm
Absorbance 1.00
Refractive index (nD) 1.4375
Viscosity 0.945 mPa s [3]
Thermochemistry
Specific
heat capacity
C
178.2 J K−1 mol−1
Std enthalpy of
formation
ΔfHo298
−300.1 kJ mol−1
Std enthalpy of
combustion
ΔcHo298
−2.5835–−2.5805 MJ mol−1
Hazards
GHS pictograms The exclamation-mark pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS) The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word DANGER
GHS hazard statements H312, H332, H360
GHS precautionary statements P280, P308+313
EU Index 616-011-00-4
EU classification Toxic T
R-phrases R61, R20/21
S-phrases 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
Flash point 63 °C (145 °F; 336 K)
Explosive limits 1.8–11.5%
LD50
  • 2.24 g kg−1 (dermal, rabbit)
  • 4.3 g kg−1 (oral, rat)
Related compounds
Related compounds
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
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Infobox references

Dimethylacetamide is the organic compound with the formula CH3C(O)N(CH3)2. This colorless, water-miscible, high boiling liquid is commonly used as a polar solvent in organic synthesis. DMA, as it often abbreviated, is miscible with most other solvents, although it is poorly soluble in aliphatic hydrocarbons.

Synthesis, reactions, applications[edit]

DMA is prepared by the reaction of dimethylamine with acetic anhydride and esters of acetic acid. Dehydration of the salt of dimethylamine and acetic acid also furnishes this compound:[4]

CH3CO2-N(CH3)2H2 → H2O + CH3CON(CH3)2

The chemical reactions of dimethylacetamide are typical of N,N-disubstituted amides. It will hydrolyze in the presence of acids:

CH3CON(CH3)2 + H2O + HCl → CH3COOH + (CH3)2NH2+Cl-

It is however resistant to bases. For this reason DMA is useful solvent for reactions involving strong bases such as sodium hydroxide.[5]

Dimethylacetamide is commonly used as a solvent for fibers (e.g., polyacrylonitrile, spandex) or in the adhesive industry.[4] It is also employed in the production of pharmaceuticals and plasticizers as a reaction medium.

References[edit]

  1. ^ "dimethylacetamide - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 2005-03-26. Identification. Retrieved 2012-04-19. 
  2. ^ Munro, D. D.; Stoughto, R. B. (1965). "Dimethylacetamide (DMAC) and Dimethylformamide (DMFA). Effect on Percutaneous Absorption". Archives of Dermatology 92 (5): 585–586. doi:10.1001/archderm.1965.01600170101020. PMID 5844405. 
  3. ^ Iloukhani, H., and K. Khanlarzadeh. "Densities, viscosities, and refractive indices for binary and ternary mixtures of N, N-dimethylacetamide (1)+ 2-methylbutan-2-ol (2)+ ethyl acetate (3) at 298.15 K for the liquid region and at ambient pressure." Journal of Chemical & Engineering Data 51.4 (2006): 1226-1231. DOI: 10.1021/je050538q
  4. ^ a b Cheung, H.; Tanke, R. S.; Torrence, G. P. (2005), "Acetic Acid", Ullmann's Encyclopedia of Industrial Chemistry, Weinheim: Wiley-VCH, doi:10.1002/14356007.a01_045.pub2 
  5. ^ Zen, S.; Kaji, E. (1977), Dimethyl nitrosuccinate, Org. Synth. 57: 60 ; Coll. Vol. 6: 503 

External links[edit]