1,1,3,3-Tetramethylguanidine

1,1,3,3-Tetramethylguanidine
Names
IUPAC name
1,1,3,3-Tetramethylguanidine[1]
Identifiers
80-70-6 N
969608
ChemSpider 59832 YesY
EC Number 201-302-7
Jmol interactive 3D Image
Image
MeSH 1,1,3,3-tetramethylguanidine
PubChem 66460
UN number 2920
Properties
C5H13N3
Molar mass 115.18 g·mol−1
Appearance Colourless liquid
Density 918 mg mL−1
Melting point −30 °C (−22 °F; 243 K)
Boiling point 160 to 162 °C (320 to 324 °F; 433 to 435 K)
Miscible
Vapor pressure 30 Pa (at 20 °C)
Acidity (pKa) 13.0±1.0[2] (pKa of conjugate acid in water)
1.469
Hazards
GHS pictograms
GHS signal word DANGER
H226, H302, H314
P280, P305+351+338, P310
C
R-phrases R22, R34
S-phrases S26, S27, S36/37/39, S45
Flash point 60 °C (140 °F; 333 K)
Explosive limits 1–7.5%
Related compounds
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

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.[3]

It was originally prepared from tetramethylthiourea via S-methylation and amination, but alternative methods start from cyanogen iodide.[4]

Uses

TMG is mainly used as a strong, non-nucleophilic base for alkylations, often as a substitute for the more expensive bases DBU and DBN.[4] 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.[5]

References

  1. "1,1,3,3-tetramethylguanidine - Compound Summary". PubChem Compound. USA: National Center for Biotechnology Information. 26 March 2005. Identification. Retrieved 10 April 2012.
  2. Kaupmees, K., Trummal, A., Leito, I. (2014). "Basicities of Strong Bases in Water: A Computational Study". Croat. Chem. Acta 87: 385395. doi:10.5562/cca2472.
  3. Rodima, Toomas; Leito, I. (2002). "Acid-Base Equilibria in Nonpolar Media. 2. Self-Consistent Basicity Scale in THF Solution Ranging from 2-Methoxypyridine to EtP1(pyrr) Phosphazene". J. Org. Chem. 67 (6): 1873–1881. doi:10.1021/jo016185p.
  4. 1 2 Ishikawa, T.; Kumamoto, T. (2006). "Guanidines in Organic Synthesis". Synthesis 2006 (5): 737–752. doi:10.1055/s-2006-926325.
  5. Geoghegan, J. T.; Roth, R. W. (2003). "Catalytic effects of 1,1,3,3-tetramethylguanidine for isocyanate reactions". J. Appl. Polymer Sci. 9 (3): 1089–1093. doi:10.1002/app.1965.070090325.
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