8068. Quinoline

Nomenclature

CAS number: 91-22-5
Leucoline; chinoleine; 1-benzazine; benzo[b]pyridine.
C9H7N; mol wt 129.16.
C 83.69%, H 5.46%, N 10.84%.

Description and references

Occurs in small amounts in coal tar. Prepd by the Skraup synthesis by heating aniline with glycerol and nitrobenzene in presence of sulfuric acid: Clarke, Davis, Org. Synth. coll. vol. I, 478 (2nd ed., 1941) 478; alternate syntheses: Manske, Chem. Rev. 30, 113 (1942); Bergstrom, ibid. 35, 150 (1944). Process based on the interaction of aniline with acetaldehyde and a formaldehyde hemiacetal: Cislak, Wheeler, US 3020281 (1962 to Reilly Tar & Chem.). Toxicity data: Smyth et al., Arch. Ind. Hyg. Occup. Med. 4, 119 (1951).

Chemical structure

Properties

Hygroscopic liquid. Absorbs as much as 22% water. Darkens on storage in ordinary, stoppered bottle. Penetrating odor, not as offensive as pyridine. Volatile with steam. d425 1.0900; mp -15°; bp760 237.7°; bp100 163.2°; bp40 136.7°; bp20 119.8°; bp10 103.8°; bp5 89.6°; bp1.0 59.7°. nD20 1.62683. Absorption spectrum: Hantzsch, Ber. 44, 1824 (1911). Weak base (neutral to phenolphthalein), forms water-soluble salts with strong acids: pK 9.5. Difficultly sol in cold water, more easily in hot water. Miscible with alcohol, ether, carbon disulfide. Dissolves sulfur, phosphorus, arsenic trioxide. Protect from light and moisture. LD50 orally in rats: 460 mg/kg (Smyth).

Derivative

Bisulfate.
C9H9NO4S; mol wt 227.24.
C 47.57%, H 3.99%, N 6.16%, O 28.16%, S 14.11%.

Properties

White to grayish-white, crystalline powder. mp 163-165°. Freely sol in water; one gram dissolves in 50 ml cold, in 9 ml boiling abs alcohol. Protect from light.

Derivative

Hydrochloride.
C9H7N.HCl; mol wt 165.62.
C 65.27%, H 4.87%, N 8.46%, Cl 21.41%.

Properties

White deliquesc crystals. mp 93-94°. Freely sol in water, alcohol, hot benzene, chloroform, sparingly in cold ether. Keep well closed and protected from light.

Derivative

Salicylate.
C16H13NO3; mol wt 267.28.
C 71.90%, H 4.90%, N 5.24%, O 17.96%.

Properties

Reddish-gray crystalline powder. Sol in 80 parts water; freely sol in alcohol, benzene, ether, glycerol, oils. Protect from light.

Derivative

Tartrate.
C43H45N3O24; mol wt 987.82.
C 52.28%, H 4.59%, N 4.25%, O 38.87%.

Properties

White crystals, pungent odor, sharp taste. mp 125° (dec). Sol in 80 parts water, 150 parts alcohol. Insol in ether.

Use

Manuf dyes; prepn hydroxyquinoline sulfate, niacin. As preservative for anatomical specimens. Solvent for resins, terpenes.

Therapeutic Category

Antimalarial.

Keywords

Antimalarial