Abbreviations DMA, DMAC, DMAc Boiling point 165 °C Formula C4H9NO | Appearance Colorless liquid Density 940 kg/m³ | |
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Dimethylacetamide
Dimethylacetamide (DMA) 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 is miscible with most other solvents, although it is poorly soluble in aliphatic hydrocarbons.
Contents
Synthesis, reactions, applications
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:
CH3CO2H·HN(CH3)2 → H2O + CH3CON(CH3)2The 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.
Dimethylacetamide is commonly used as a solvent for fibers (e.g., polyacrylonitrile, spandex) or in the adhesive industry. It is also employed in the production of pharmaceuticals and plasticizers as a reaction medium.
Dimethylacetamide is also used as an excipient in drugs, e.g. in Vumon (teniposide), Busulfex (busulfan) or Amsidine (amsacrine).
Toxicity
Dimethylacetamide is a medium potency reproductive toxicant (toxic for reproduction, category 1B) and may damage fertility or the unborn child. It is harmful in contact with skin or if inhaled, and causes serious eye irritation.
Dimethylacetamide can cause hepatotoxicity, including occupational dimethylacetamide exposure-induced hepatotoxicity. At high doses (400 mg/kg bodyweight daily), dimethylacetamide causes effects on the central nervous system (e.g. depression, hallucinations and delusion).
Dimethylacetamide may be incompatible with polycarbonate or ABS. Devices (e.g. syringes) that contain polycarbonate or ABS can dissolve when coming into contact with dimethylacetamide.
Regulation
In 2011, dimethylacetamide was identified in the EU as a Substance of very high concern (SVHC) because of its reproductive toxicity. In 2014, the European Commission has started an investigation to restrict the use of dimethylacetamide in the EU according to REACH.
In 2015, the CNESST (Committee on Standards, Equity, Health and Safety at Work in Quebec) has adopted a tightened classification of dimethylacetamide: