Quinaldine

Quinaldine
Names
Preferred IUPAC name
2-Methylquinoline
Other names
Quinaldine, α-methylquinoline, chinaldine, khinaldin
Identifiers
CAS Number
3D model (JSmol)
ChEBI
ChEMBL
ChemSpider
ECHA InfoCard 100.001.896
EC Number
  • 202-085-1
PubChem CID
UNII
CompTox Dashboard (EPA)
InChI
  • InChI=1S/C10H9N/c1-8-6-7-9-4-2-3-5-10(9)11-8/h2-7H,1H3 checkY
    Key: SMUQFGGVLNAIOZ-UHFFFAOYSA-N checkY
  • InChI=1/C10H9N/c1-8-6-7-9-4-2-3-5-10(9)11-8/h2-7H,1H3
SMILES
  • Cc1nc2ccccc2cc1
Properties
Chemical formula
C10H9N
Molar mass 143.19 g/mol
Appearance colorless oil
Density 1.058 g/cm3
Melting point −2 °C (28 °F; 271 K)
Boiling point 248 °C (478 °F; 521 K)
Solubility in water
Insoluble
Hazards
GHS labelling:
Pictograms
GHS07: Exclamation mark
Signal word
Warning
Hazard statements
H302, H312, H319
Precautionary statements
P264, P270, P280, P301+P312, P302+P352, P305+P351+P338, P312, P322, P330, P337+P313, P363, P501
NFPA 704 (fire diamond)
NFPA 704 four-colored diamond
2
2
0
Flash point 79 °C (174 °F; 352 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
☒N verify (what is checkY☒N ?)
Infobox references

Quinaldine or 2-methylquinoline is an organic compound with the formula CH3C9H6N. It is one of the methyl derivatives of the heterocyclic compound quinoline. It is bioactive and is used in the preparation of various dyes. It is a colorless oil but commercial samples can appear colored.[1]

Production and reactions

Quinaldine is recovered from coal tar. It can be prepared from aniline and paraldehyde via Skraup synthesis or from aniline and crotonaldehyde via Doebner-von Miller variation of the Skraup reaction.[1]

Hydrogenation of quinaldine gives 2-methyltetrahydroquinoline. This reduction can be conducted enantioselectively.[2] Oxidation with selenium dioxide give the aldehyde 2-formylquinoline.[3]

Properties

Quinaldine has critical point at 787 K and 4.9 MPa and its refractive index is 1.8116.

Uses

Quinoline Yellow is a popular dye derived from quinaldine.
Quinaldine Red, a pH indicating dye.

Quinaldine is used in manufacturing anti-malaria drugs, dyes and food colorants (e.g., Quinoline Yellows, pinacyanol). It is the precursor to the pH indicator Quinaldine Red.

Quinaldine sulfate is an anaesthetic used in fish transportation.[4] In some Caribbean islands it is used to facilitate the collection of tropical fish from reefs.

See also

  • Lepidine, the isomer with the methyl group in position 4.

References

  1. ^ a b Gerd Collin; Hartmut Höke. "Quinoline and Isoquinoline". Ullmann's Encyclopedia of Industrial Chemistry. Weinheim: Wiley-VCH. doi:10.1002/14356007.a22_465. ISBN 978-3-527-30673-2.
  2. ^ Chen, Fei; Ding, Zi-Yuan; He, Yan-Mei; Fan, Qing-Hua (2015). "Synthesis of Optically Active 1,2,3,4-Tetrahydroquinolines via Asymmetric Hydrogenation Using Iridium-Diamine Catalyst". Org. Synth. 92: 213–226. doi:10.15227/orgsyn.092.0213.
  3. ^ H. A. Riley, A. R. Gray (1935). "Phenylglyoxal". Organic Syntheses. 15: 67. doi:10.15227/orgsyn.015.0067.
  4. ^ Blasiola G. C. Jr. (1977). "Quinaldine sulphate, a new anaesthetic formulation for tropical marine fishes". Journal of Fish Biology. 10 (2): 113–119(7). doi:10.1111/j.1095-8649.1977.tb04048.x.