N,N-Dimethylformamide (cas:68-12-2)

Dimethylformamide is abbreviated as DMF. It is a compound formed by replacing the hydroxyl group of formic acid with a dimethylamino group, with the molecular formula HCON(CH3)2. It is a colorless, transparent, high-boiling liquid with a faint amine odor and a relative density of 0.9445 (25°C). Melting point -61°C, boiling point 152.8°C, flash point 57.78°C. Vapor density 2.51. Vapor pressure 0.49 kPa (3.7 mmHg at 25°C). Autoignition point 445°C. Explosion limits of vapor-air mixtures 2.2–15.2%. It can catch fire or explode when exposed to open flames or high heat. It can react violently with concentrated sulfuric acid and fuming nitric acid, even causing explosions. It is miscible with water and most organic solvents. It is a commonly used solvent for chemical reactions. Pure dimethylformamide is odorless, but industrial-grade or degraded dimethylformamide has a fishy smell due to impurities of dimethylamine. The name comes from it being a dimethyl-substituted formamide (the amide of formic acid), with both methyl groups attached to the nitrogen atom. Dimethylformamide is a high-boiling polar (hydrophilic) aprotic solvent that can promote SN2 reaction mechanisms. Dimethylformamide is made from formic acid and dimethylamine. Dimethylformamide is unstable in the presence of strong bases like sodium hydroxide or strong acids like hydrochloric acid or sulfuric acid, especially at high temperatures, and hydrolyzes into formic acid and dimethylamine. It is stable in air and when heated to boiling, but at temperatures above 350°C it loses water, producing carbon monoxide and dimethylamine. N,N-Dimethylformamide is an excellent aprotic polar solvent, able to dissolve most organic and inorganic substances, and is miscible with water, alcohols, ethers, aldehydes, ketones, esters, halogenated hydrocarbons, and aromatics. In N,N-dimethylformamide, the positively charged end of the molecule is surrounded by methyl groups, creating steric hindrance that prevents anions from approaching, allowing association primarily with cations. The activity of exposed anions is much higher than that of solvated anions. Many ionic reactions proceed more easily in N,N-dimethylformamide than in typical protic solvents. For example, at room temperature, carboxylates react with halogenated hydrocarbons in N,N-dimethylformamide to produce high yields of esters, making it particularly suitable for the synthesis of sterically hindered esters.