1,1,3,3-Tetramethylguanidine
Skeletal formula of 1,1,3,3-tetramethylguanidine
Ball and stick model of 1,1,3,3-tetramethylguanidine
Spacefill model of 1,1,3,3-tetramethylguanidine
Names
Preferred IUPAC name
N,N,N′,N′-Tetramethylguanidine
Identifiers
3D model (JSmol)
969608
ChemSpider
ECHA InfoCard 100.001.185
EC Number
  • 201-302-7
MeSH 1,1,3,3-tetramethylguanidine
UNII
UN number 2920
  • InChI=1S/C5H13N3/c1-7(2)5(6)8(3)4/h6H,1-4H3 checkY
    Key: KYVBNYUBXIEUFW-UHFFFAOYSA-N checkY
  • CN(C)C(=N)N(C)C
Properties
C5H13N3
Molar mass 115.180 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[1] (pKa of conjugate acid in water)
1.469
Hazards
GHS labelling:
GHS02: Flammable GHS05: Corrosive GHS07: Exclamation mark
Danger
H226, H302, H314
P280, P305+P351+P338, P310
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, as judged by the high pKa of it conjugate acid.[2]

It was originally prepared from tetramethylthiourea via S-methylation and amination, but alternative methods start from cyanogen iodide.[3]

Uses

Tetramethylguanidine is mainly used as a strong, non-nucleophilic base for alkylations, often as a substitute for the more expensive DBU and DBN.[3] 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.[4]

References

  1. ↑ Kaupmees, K.; Trummal, A.; Leito, I. (2014). "Basicities of Strong Bases in Water: A Computational Study". Croat. Chem. Acta. 87 (4): 385–395. doi:10.5562/cca2472.
  2. ↑ 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. PMID 11895405.
  3. 1 2 Ishikawa, T.; Kumamoto, T. (2006). "Guanidines in Organic Synthesis". Synthesis. 2006 (5): 737–752. doi:10.1055/s-2006-926325.
  4. ↑ Geoghegan, J. T.; Roth, R. W. (2003). "Catalytic Effects of 1,1,3,3-Tetramethylguanidine for Isocyanate Reactions". J. Appl. Polym. Sci. 9 (3): 1089–1093. doi:10.1002/app.1965.070090325.
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