Names | |
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Preferred IUPAC name
2,4,6-Trimethylpyridine | |
Identifiers | |
ECHA InfoCard | 100.003.286 |
PubChem
CID
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UNII | |
CompTox Dashboard (
EPA)
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Properties | |
C8H11N | |
Molar mass | 121.18 g· mol−1 |
Appearance | colourless liquid with pyridine-like smell [1] |
Melting point | -44,5 °C |
Boiling point | 171–172 °C [1] |
35 g·l−1 (20 °C) [1] | |
Vapor pressure | 4 hPa (20 °C) [1] |
Acidity (pKa) | 7.43 (25 °C) [2] |
Except where otherwise noted, data are given for materials in their
standard state (at 25 °C [77 °F], 100 kPa).
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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.
The compound has a refractive index of 1.4959 (25 °C). [3]
2,4,6-Trimethylpyridine was isolated from Dippel's oil in 1854. [4] [5] A synthesis can be carried out analogously to the Hantzsch's dihydropyridine synthesis from ethyl acetoacetate (as β-ketocarbonyl compound), acetaldehyde and ammonia in the ratio 2: 1: 1. [6]
By oxidation of the methyl groups with potassium permanganate collidinic acid is obtained. [7]
2,4,6-Trimethylpyridine is used in organic syntheses (for example, for dehydrohalogenation [8]), by binding the formed hydrogen halides.