Benzopyridine

Quinoline

Names
Preferred IUPAC name Quinoline
Systematic IUPAC name 1-Benzopyridine Benzo[b]pyridine 2-Azabicyclo[4.4.0]deca-1(6),2,4,7,9-pentaene 2-Azabicyclo[4.4.0]deca-1,3,5,7,9-pentaene Benzo[b]azine Benzo[b]azabenzene
Other names 1-Azanaphthalene 1-Benzazine Benzazine Benzazabenzene Benzopyridine 1-Benzine Quinolin Chinoline Chinoleine Chinolin Leucol Leukol Leucoline
Identifiers
CAS Number	91-22-5 Y
3D model (JSmol)	Interactive image
3DMet	B00959
ChEBI	CHEBI:17362 Y
ChemSpider	6780 Y
ECHA InfoCard	100.001.865
EC Number	202-051-6
KEGG	C06413 Y
MeSH	Quinolines
PubChem CID	7047
RTECS number	VA9275000
UNII	E66400VT9R Y
UN number	2656
InChI InChI=1S/C9H7N/c1-2-6-9-8(4-1)5-3-7-10-9/h1-7H Y Key: SMWDFEZZVXVKRB-UHFFFAOYSA-N Y InChI=1/C9H7N/c1-2-6-9-8(4-1)5-3-7-10-9/h1-7H Key: SMWDFEZZVXVKRB-UHFFFAOYAU
SMILES n1cccc2ccccc12 C1=CC=C2C(=C1)C=CC=N2
Properties
Chemical formula	C9H7N
Molar mass	129.16 g/mol
Appearance	yellowish oily liquid
Density	1.093 g/mL
Melting point	−15 °C (5 °F; 258 K)
Boiling point	237 °C (459 °F; 510 K) /760 mm Hg, 108 to 110 °C/11 mm Hg
Solubility in water	Slightly soluble
Solubility	Soluble in alcohol, ether, and carbon disulfide
Acidity (pKa)	4.85 (conjugated acid)
Magnetic susceptibility (χ)	-86.0·10−6 cm3/mol
Thermochemistry
Std enthalpy of formation (ΔfHo298)	174.9 kJ mol−1
Hazards
R-phrases (outdated)	R21, R22
S-phrases (outdated)	S26, S27, S28, S29, S30, Template:S31, Template:S32, S33, Template:S34, S35, S36
NFPA 704	1 2 0
Flash point	101 °C (214 °F; 374 K)
Autoignition temperature	400 °C (752 °F; 673 K)
Lethal dose or concentration (LD, LC):
LD50 (median dose)	331 mg/kg
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Quinoline is a heterocyclic aromatic organic compound with the chemical formula C₉H₇N. It is a colorless hygroscopic liquid with a strong odor. Aged samples, especially if exposed to light, become yellow and later brown. Quinoline is only slightly soluble in cold water but dissolves readily in hot water and most organic solvents. Quinoline itself has few applications, but many of its derivatives are useful in diverse applications. A prominent example is quinine, an alkaloid found in plants. 4-Hydroxy-2-alkylquinolines (HAQs) are involved in antibiotic resistance.

Quinoline was first extracted from coal tar in 1834 by Friedlieb Ferdinand Runge; he called quinoline leukol ("white oil" in Greek). Coal tar remains the principal source of commercial quinoline. In 1842, French chemist Charles Gerhardt obtained a compound by dry distilling quinine, strychnine, or cinchonine with potassium hydroxide; he called the compound Chinoilin or Chinolein. Runge's and Gephardt's compounds seemed to be distinct isomers because they reacted differently. However, the German chemist August Hoffmann eventually recognized that the differences in behaviors was due to the presence of contaminants and that the two compounds were actually identical.

Like other nitrogen heterocyclic compounds, such as pyridine derivatives, quinoline is often reported as an environmental contaminant associated with facilities processing oil shale or coal, and has also been found at legacy wood treatment sites. Owing to its relatively high solubility in water quinoline has significant potential for mobility in the environment, which may promote water contamination. Quinoline is readily degradable by certain microorganisms, such as Rhodococcus species Strain Q1, which was isolated from soil and paper mill sludge.