Login
Login

2,4,6-Trimethylpyridine

{{Chembox

|ImageFile = 2,4,6-Trimethylpyridine.svg

|ImageSize = 200px

|PIN = 2,4,6-Trimethylpyridine

| Section1 = {{Chembox Identifiers

| CASNo = 108-75-8

| CASNo_Ref = {{cascite|correct|CAS}}

| UNII_Ref = {{fdacite|correct|FDA}}

| UNII = 7IE4BK5J5V

| PubChem = 7953

}}

|Section2 = {{Chembox Properties

|Formula = C8H11N

|MolarMass = 121.18 g·mol−1

|Appearance = colourless liquid with pyridine-like smell{{GESTIS|ZVG=18380|CAS=108-75-8|Name=2,4,6-Trimethylpyridin|Date=27 July 2017}}

|MeltingPt = -44,5 °C

|BoilingPt = 171–172 °C

|Solubility = 35 g·l−1 (20 °C)

|VaporPressure = 4 hPa (20 °C)

|pKa = 7.43 (25 °C)Zvi Rappoport: CRC Handbook of Tables for Organic Compound Identification, Third Edition, CRC Press, Boca Raton, Florida, 1984, {{ISBN|0-8493-0303-6}}, S. 438.

}}

}}

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 of 1.4959 (25 °C).{{cite book|editor=David R. Lide|title=CRC Handbook of Chemistry and Physics|edition= 90th|id=(Internet-Version: 2010)|publisher= CRC Press/Taylor and Francis|location=Boca Raton, FL|chapter=Physical Constants of Organic Compounds|pages=3–510}}

Preparation

2,4,6-Trimethylpyridine was isolated from Dippel's oil in 1854.Collidin. In: Heinrich August Pierer, Julius Löbe (Hrsg.): Universal-Lexikon der Gegenwart und Vergangenheit. 4. Auflage. Band 4. Altenburg 1858, S. 262 ([http://www.zeno.org/Pierer-1857/A/Collidin zeno.org]).Friedrich Auerbach: „Ueber ein neues Collidin“, in: Berichte der deutschen chemischen Gesellschaft, 1892, 25 (2), S. 3485–3490 ({{doi|10.1002/cber.189202502219}}). 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.T. Laue, A. Plagens: Namen- und Schlagwort-Reaktionen der Organischen Chemie, 5. Auflage, Teubner Verlag, Wiesbaden 2006, {{ISBN|3-8351-0091-2}}, S. 172.

Use

By oxidation of the methyl groups with potassium permanganate collidinic acid is obtained.{{citation|author1=Hong-Lin Zhu|author2=Wei Xu|author3=Jian-Fei Wang|author4=Yue-Qing Zheng|periodical=Synthetic Metals|title=Synthesis, crystal structures and properties of two supramolecular polymers constructed by lanthanide with pyridine-2,4,6-tricarboxylic acid|volume=162|issue=13–14|pages=1327–1334|date=2012|language=German|doi=10.1016/j.synthmet.2012.05.016

}}

2,4,6-Trimethylpyridine is used in organic syntheses (for example, for dehydrohalogenation{{RömppOnline |Name=Kollidin |Datum=27 July 2017 |ID= RD-11-01589}}), by binding the formed hydrogen halides.

See also

References

{{DEFAULTSORT:Trimethylpyridine, 2, 4, 6-}}

Category:Pyridines

Category:Non-nucleophilic bases