5-Ethyl-2-methylpyridine

5-Ethyl-2-methylpyridine is an organic compound with the formula (C2H5)(CH3)C5H3N. One of several isomeric pyridines with this formula, this derivative is of interest because it is efficiently prepared from simple reagents and it is a convenient precursor to nicotinic acid, a form of vitamin B3. 5-Ethyl-2-methylpyridine is a colorless liquid.[1]

5-Ethyl-2-methylpyridine
Names
Other names
aldehyde-collidine, MEP, 5-Ethyl-2-picoline
Identifiers
3D model (JSmol)
109269
ChEMBL
ChemSpider
ECHA InfoCard 100.002.955 Edit this at Wikidata
EC Number
  • 203-250-0
RTECS number
  • TJ6825000
UNII
UN number 2300
  • InChI=1S/C8H11N/c1-3-8-5-4-7(2)9-6-8/h4-6H,3H2,1-2H3
    Key: NTSLROIKFLNUIJ-UHFFFAOYSA-N
  • CCC1=CN=C(C=C1)C
Properties
C8H11N
Molar mass 121.183 g·mol−1
Appearance colorless liquid
Density 0.9208 g/cm3
Melting point −70.3 °C (−94.5 °F; 202.8 K)
Boiling point 178 °C (352 °F; 451 K)
1.2g/100 mL
Hazards
GHS labelling:
GHS05: CorrosiveGHS06: ToxicGHS07: Exclamation mark
Danger
H302, H311, H314, H315, H317, H319, H331, H412
P260, P261, P264, P270, P271, P272, P273, P280, P301+P312, P301+P330+P331, P302+P352, P303+P361+P353, P304+P340, P305+P351+P338, P310, P311, P312, P321, P322, P330, P332+P313, P333+P313, P337+P313, P361, P362, P363, P403+P233, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Synthesis and reactions

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5-Ethyl-2-methylpyridine is produced by condensation of paraldehyde (a derivative of acetaldehyde) and ammonia:[2]

4 CH3CHO + NH3 → (C2H5)(CH3)C5H3N + 4 H2O

The conversion is an example of a structurally complex compound efficiently made from simple precursors. Under related conditions, the condensation of acetaldehyde and ammonia delivers 2-picoline.

Oxidation of 5-ethyl-2-methylpyridine with nitric acid gives nicotinic acid via the decarboxylation of 2,5-pyridinedicarboxylic acid.[1]

Toxicity

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Like most alkylpyridines, the LD50 of 5-ethyl-2-methylpyridine is modest, being 368 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.
  2. ^ Frank, R. L.; Pilgrim, F. J.; Riener, E. F. (1950). "5-Ethyl-2-Methylpyridine (2-Picoline, 5-ethyl-)". Organic Syntheses. 30: 41. doi:10.15227/orgsyn.030.0041.