N, n-dimethylacetamide, also known as acetyl dimethylamine, acetyl dimethylamine, referred to as DMAC, colorless transparent liquid, flammable. It can be mixed with organic solvents such as water, alcohol, ether, ester, benzene, trichloromethane and aromatic compounds. Freezing point -20℃, boiling point 166℃, 96℃ (10.7kPa), 85-87℃ (4.4kPa), 74-74.5℃ (3.47kPa), 66-67℃ (2.0kPa), 62-63℃ (1.6kPa), relative density 0.9366 (25/4℃). 0.9599 (0/4℃), refractive index 1.4380. Flash point (open cup) 70℃. It is an aprotic highly polar solvent with a slight ammonia odor, strong solubility, a wide range of soluble substances, and can be miscible with water, aromatic compounds, esters, ketones, alcohols, ethers, benzene and trichloromethane, and can activate compound molecules, so it is widely used as a solvent and catalyst.