| 918 kg/m³|| Colourless liquid|
Tetramethylguanidine is an organic compound with the formula HNC(N(CH3)2)2. This colourless liquid is a strong base with a higher pKa than typical amines.
It was originally prepared from tetramethylthiourea via S-methylation and amination, but alternative methods start from cyanogen iodide.
TMG is mainly used as a strong, non-nucleophilic base for alkylations, often as a substitute for the more expensive bases DBU and DBN. Since it is highly water-soluble, it is easily removed from mixtures in organic solvents. It is also used as a base-catalyst in the production of polyurethane.