This article relies largely or entirely on a single source. (March 2024) |
4-Methylpyridine is the organic compound with the formula CH3C5H4N. It is one of the three isomers of methylpyridine. This pungent liquid is a building block for the synthesis of other heterocyclic compounds. Its conjugate acid, the 4-methylpyridinium ion, has a pKa of 5.98, about 0.7 units above that of pyridine itself.[1]
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| Names | |
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| Preferred IUPAC name
4-Methylpyridine | |
| Other names
4-Picoline
γ-picoline | |
| Identifiers | |
3D model (JSmol)
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| ChEBI | |
| ChemSpider | |
| ECHA InfoCard | 100.003.298 |
PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C6H7N | |
| Molar mass | 93.129 g·mol−1 |
| Appearance | colorless liquid |
| Density | 0.957 g/mL |
| Melting point | 2.4 °C (36.3 °F; 275.5 K) |
| Boiling point | 145 °C (293 °F; 418 K) |
| Miscible | |
| -59.8·10−6 cm3/mol | |
| Hazards | |
| Flash point | 39 °C (102 °F; 312 K) |
| 538 °C; 1,000 °F; 811 K | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Production and uses
edit4-Methylpyridine is both isolated from coal tar and is synthesized industrially. It forms via the reaction of acetaldehyde and ammonia in the presence of an oxide catalyst. The method also affords some 2-methylpyridine.
4-Methylpyridine is of little intrinsic value but is a precursor to other commercially significant species, often of medicinal interest. For example, ammoxidation of 4-methylpyridine gives 4-cyanopyridine, the precursor to a variety of other derivatives such as the antituberculosis drug isoniazid.[1]
Toxicity
editLike most alkylpyridines, the LD50 of 4-methylpyridine is modest, being 1290 mg/kg (oral, rat).[1]
References
edit- ^ a b c Shimizu, Shinkichi; Watanabe, Nanao; Kataoka, Toshiaki; Shoji, Takayuki; Abe, Nobuyuki; Morishita, Sinji; Ichimura, Hisao (2007). "Pyridine and Pyridine Derivatives". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_399. ISBN 978-3527306732.