8014. 1H-Pyrrole

Nomenclature

CAS number: 109-97-7
Azole; imidole; divinylenimine.
C4H5N; mol wt 67.09.
C 71.61%, H 7.51%, N 20.88%.

Description and references

A constituent of coal tar and bone oil: Runge, Ann. Phys. 31, 67 (1834). Prepd industrially by fractional distillation of bone oil, or by the thermal decompn of ammonium mucate with glycerol or mineral oil: McElvain, Bolliger, Org. Synth. coll. vol. I (2nd ed., 1941) p 473; Blicke, Powers, Ind. Eng. Chem. 19, 1334 (1927). Also formed on heating of albumin; on heating sheep's wool with aq barium hydroxide soln; by pyrolysis of gelatin. Alternate prepns from acetaldehyde and ammonia: Tschitschibabin, Chem. Zentralbl. 1916, I, 920; from succindialdehyde with ammonia and acetic acid: Harries, Ber. 34, 1496 (1901); 35, 1183 (1902); distilling succinimide with zinc or sodium: Bell, Bernthsen, Ber. 13, 877, 1049 (1880). Purification and physical properties: R. V. Helm et al., J. Phys. Chem. 62, 858 (1958). Review: Fischer-Orth, Die Chemie des Pyrrols (Leipzig, 1934-1940); E. Vittort, L. R. Anderson in Kirk-Othmer Encyclopedia of Chemical Technology vol. 19 (Wiley-Interscience, New York, 3rd ed., 1982) pp 499-520.

Chemical structure

Properties

Liquid. Agreeable empyreumatic odor resembling that of chloroform. Colorless when freshly distilled, darkens unless every trace of oxygen is removed. d420 0.9691. bp760 129.8°. Best distilled in vacuo. nD20 1.5085. Flash pt, closed cup: 102°F (39.0°C). Absorption spectrum: Menczel, Phys. Chem. 125, 161; Chem. Zentralbl. 1927, I, 2510. Sparingly sol in water; freely sol in alcohol, benzene, ether. Insol in aq alkalies. Sol in dil acids with decompn. Solns in dil HCl yield pyrrole red, an amorphous, orange-colored substance; also polymerization takes place under the influence of acids and glycols.