2-Methylpyridine
From Wikipedia, the free encyclopedia
| 2-Methylpyridine | |
|---|---|
 |
 |
| Other names | 2-picoline |
| Identifiers | |
| CAS number | [109-06-8] |
| Properties | |
| Molecular formula | C6H7N |
| Molar mass | 93.13 g/mol |
| Appearance | Faintly yellow-green clear liquid |
| Density | 0.943 g/mL |
| Melting point |
-70°C |
| Boiling point |
128-129°C |
| Solubility in water | Miscible |
| Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa) Infobox disclaimer and references |
|
2-Methylpyridine, or 2-picoline, is the compound described with formula 2-CH3C5H4N. 2-picoline is a colorless liquid that has an unpleasant odor similar to pyridine. Pyridines including 2-picoline are most crudely prepared by the reaction of acetylene and hydrogen cyanide.
[edit] Synthesis
2-Picoline was the first pyridine compound reported to be isolated in pure form. It was isolated from coal tar in 1846 by T. Anderson.[1] It is now mainly produced by two principal routes, the condensation of acetaldehyde, formaldehyde, and ammonia and the cyclization of nitriles and acetylene. One example of such reaction is the combination of acetaldehyde and ammonia:
Approximately 8000 t/a was produced worldwide in 1989.[2]
[edit] Uses
The principal application of 2-picoline is as a precursor of 2-vinylpyridine. The formation of 2-vinylpyridine is achieved by the addition of aqueous formaldehyde to 2-picoline, followed by a dehydration of the resulting alcohol:
The copolymerization of 2-vinylpyridine, butadiene and styrene is used as an adhesive for textile tire cord. 2-picoline is also a precursor to the agrichemical, nitrapyrin, which prevents loss of ammonia from fertilizers.[2]
2-Picoline is a versatile building block and can be used as a precursor to a variety of derivatives . For example, oxidation by KMnSO4 affords picolinic acid:[2]
[edit] References
- ^ Anderson, T. (1846). "On the constitution and properties of Picoline, a new organic base from Coal Tar" (Free full text at Google Books). Edinburgh New Phil. J. XLI: 146–156; 291–300.
- ^ a b c Shinkichi Shimizu, Nanao Watanabe, Toshiaki Kataoka, Takayuki Shoji, Nobuyuki Abe, Sinji Morishita, Hisao Ichimura. (2002). "Pyridine and Pyridine Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. doi:.
- Eric F. V. Scriven, Ramiah Murugan. 'Pyridine and Pyridine Derivatives', Kirk-Othmer Encyclopedia of Chemical Technology, (2005). DOI: 10.1002/0471238961.1625180919031809.a01.pub2
