4-Methylpyridine

(Redirected from 4-Picoline)

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]

4-Methylpyridine
Names
Preferred IUPAC name
4-Methylpyridine
Other names
4-Picoline
γ-picoline
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.003.298 Edit this at Wikidata
UNII
  • InChI=1S/C6H7N/c1-6-2-4-7-5-3-6/h2-5H,1H3 ☒N
    Key: FKNQCJSGGFJEIZ-UHFFFAOYSA-N ☒N
  • Cc1ccncc1
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

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4-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

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Like most alkylpyridines, the LD50 of 4-methylpyridine is modest, being 1290 mg/kg (oral, rat).[1]

References

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  1. ^ 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.