4963. Indole

Nomenclature

CAS number: 120-72-9
2,3-Benzopyrrole.
C8H7N; mol wt 117.15.
C 82.02%, H 6.02%, N 11.96%.

Description and references

Obtained from the 240-260° fraction from coal tar: Weissgerber, Ber. 43, 3520 (1910); from feces: Bergeim, J. Biol. Chem. 32, 17 (1917). Prepn from o-formotoluide: Tyson, Org. Synth. coll. vol. III, 479 (1955); by dehydrocyclizing ortho alkyl anilines: Erner et al., US 2953575 (1960 to Houdry Process); from N-(2-tolyl)-N′-methyl-N′-phenylformamidine: Lorenz et al., J. Org. Chem. 30, 2531 (1965). Toxicity data: Smyth et al., Am. Ind. Hyg. Assoc. J. 23, 95 (1962). Comprehensive review: Van Order, Lindwall, Chem. Rev. 30, 69 (1942); D. W. Bannister in Kirk-Othmer Encyclopedia of Chemical Technology vol. 13 (Wiley-Interscience, New York, 3rd ed., 1981) pp 213-222.

Chemical structure

Properties

Leaflets, mp 52°. bp762 253°; bp28 128-133°. Intense fecal odor. Volatile with steam. Soluble in hot water, hot alcohol, ether, benzene. LD50 orally in rats: 1 g/kg (Smyth).

Use

In highly dil solns the odor is pleasant, hence indole has been used in perfumery.