2,6-Lutidine

2,6-Lutidine[1]
IUPAC name

2,6-Dimethylpyridine
Other names

Lutidine
Identifiers
CAS number 108-48-5 Y
PubChem 7937
ChemSpider 7649 Y
UNII 15FQ5D0T3P Y
Jmol-3D images Image 1
Properties
Molecular formula C7H9N
Molar mass 107.153 g/mol
Appearance Clear oily liquid
Density 0.9252
Melting point

−5.8 °C, 267 K, 22 °F
Boiling point

144 °C, 417 K, 291 °F
Solubility in water 27.2% at 45.3 °C
Acidity (pKa) 6.60[2]
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

2,6-Lutidine is a natural heterocyclic aromatic organic compound. It has been isolated from the basic fraction of coal tar and from bone oil.[1] It is a dimethyl substituted derivative of pyridine. It has been detected in waste water from oil shale processing sites and former creosoting facilities. 2,6-Lutidine has been evaluated for use as a food additive owing to its nutty aroma when present in solution at very low concentrations, however the neat solvent has a pungent, noxious odor.[3]

2,6-Lutidine is weakly nucleophilic, due to the steric effects of the two methyl groups on the ring nitrogen. It is moderately basic, with a pKa of 6.60.[2] In organic synthesis, 2,6-lutidine is thus widely used as a sterically hindered mild base.

Environmental Properties

Though pyridine is an excellent source of carbon, nitrogen, and energy for certain microorganisms, methylation significantly retards degradation of the pyridine ring. 2,6-Lutidine was found to be significantly more resistant to microbiological degradation than any of the picoline isomers or 2,4-lutidine in soil.[4] Significant volatilization loss was observed in liquid media. Estimated time for complete degradation was > 30 days.[5]

See also

References

  1. ^ a b Merck Index, 11th Edition, 5485.
  2. ^ a b Zvi Rappoport: CRC Handbook of Tables for Organic Compound Identification, Third Edition, CRC Press, Boca Raton, Florida, 1984, ISBN 0-8493-0303-6, p. 438.
  3. ^ Sims, G. K. and E.J. O'Loughlin. 1989. Degradation of pyridines in the environment. CRC Critical Reviews in Environmental Control. 19(4): 309–340.
  4. ^ Sims, G. K. and L.E. Sommers. 1985. Degradation of pyridine derivatives in soil. Journal of Environmental Quality. 14: 580–584.
  5. ^ Sims, G. K. and L.E. Sommers. 1986. Biodegradation of pyridine derivatives in soil suspensions. Environmental Toxicology and Chemistry. 5: 503–509.