2,4,6-Trimethylpyridine (2,4,6-collidine) is an organic compound which belongs to the
heterocycles (more precisely,
heteroaromatics). It consists of a
pyridine ring substituted with three
methyl groups. It belongs to the substance group of the
collidines, a group of six
constitutional isomers. 2,4,6-trimethylpyridine is the most well-known isomer of this group.
Properties
The compound has a
refractive index
In optics, the refractive index (or refraction index) of an optical medium is the ratio of the apparent speed of light in the air or vacuum to the speed in the medium. The refractive index determines how much the path of light is bent, or refrac ...
of 1.4959 (25 °C).
Preparation
2,4,6-Trimethylpyridine was isolated from
Dippel's oil in 1854. A synthesis can be carried out analogously to the Hantzsch's dihydropyridine synthesis from ethyl acetoacetate (as β-ketocarbonyl compound),
acetaldehyde and
ammonia
Ammonia is an inorganic chemical compound of nitrogen and hydrogen with the chemical formula, formula . A Binary compounds of hydrogen, stable binary hydride and the simplest pnictogen hydride, ammonia is a colourless gas with a distinctive pu ...
in the ratio 2: 1: 1.
Use
By oxidation of the methyl groups with
potassium permanganate collidinic acid is obtained.
2,4,6-Trimethylpyridine is used in organic syntheses (for example, for
dehydrohalogenation), by binding the formed
hydrogen halides.
See also
*
2,6-Dimethylpyridine (lutidine)
References
{{DEFAULTSORT:Trimethylpyridine, 2, 4, 6-
Pyridines
Non-nucleophilic bases