1,3-Dimethyl-2-imidazolidinone

1,3-Dimethyl-2-imidazolidinone is a cyclic urea used as a high-boiling polar aprotic solvent. This colourless, highly polar solvent has high thermal and chemical stability. Together with homologous solvent DMPU, since the 1970s it serves as an analog of tetramethylurea. It can be prepared from 1,2-dimethylethylenediamine by reaction with phosgene.

History

In 1940 Du Pont applied for a patent on acetylene storage in many polar organic solvents, one of which was 1,3-dimethyl-2-imid azolidone. The company filed another patent on a method of synthesizing the same compound, albeit called s-dimethylethyleneurea, in 1944.
Soon thereafter William Boon from the Imperial Chemical Industries published a different synthesis method of what he called 1:3-dimethyliminazolid-2-one. The compound was more closely studied in the 1960s, with its adoption as a solvent starting in the 1970s.

Solvent

DMI has excellent solvating ability for both inorganic and organic compounds. In many applications, DMI can be used as a substitute or replacement for the carcinogenic solvent HMPA. Compared to the 6-atom ring analog, it has an advantage of lower viscosity.
DMI is used in a variety of applications including detergents, dyestuffs, electronic materials and in the manufacture of polymers.
DMI is toxic in contact with skin.