591. 4-Aminoantipyrine

Nomenclature

CAS number: 83-07-8
4-Amino-1,2-dihydro-1,5-dimethyl-2-phenyl-3H-pyrazol-3-one; ampyrone; 4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one; 1,5-dimethyl-2-phenyl-4-aminopyrazolone; 1-phenyl-2,3-dimethyl-4-amino-4-pyrazolone.
C11H13N3O; mol wt 203.24.
C 65.01%, H 6.45%, N 20.68%, O 7.87%.

Description and references

Reacts with phenols in the presence of alkaline oxidizing agents to form intensely colored compounds. Prepn: E. Waser, Helv. Chim. Acta 8, 117 (1925); L. Freedman, A. E. Sherndal, US 1877166 (1933 to H. A. Metz Labs.). Colorometric reaction with phenols: E. Emerson, J. Org. Chem. 8, 417 (1943); D. Svobodová, J. Gasparic, Mikrochim. Acta 59, 384 (1971); Y. Fiamegos et al., Anal. Chim. Acta 467, 105 (2002). 13C-NMR spectrum: S. P. Singh et al., J. Pharm. Sci. 68, 470 (1979). Thermodynamic properties: I. Katime, F. A. Herraiz, Thermochim. Acta 49, 139 (1981). Metabolite of aminopyrine, q.v.: E. S. Vesell et al., Clin. Pharmacol. Ther. 20, 661 (1976); G. F. Lockwood, J. B. Houston, J. Pharm. Pharmacol. 31, 787 (1979).

Chemical structure

Properties

Pale yellow crystals from benzene, mp 109°. Sol in water, ethanol, benzene; sparingly sol in ether.

Caution

Irritating to eyes, respiratory system and skin.

Use

Reagent for spectrophotometric and colorimetric determn of phenols; in analytical chemistry for trace phenol determn in water.