7277. Phenylbutazone

Nomenclature

CAS number: 50-33-9
4-Butyl-1,2-diphenyl-3,5-pyrazolidinedione; 4-butyl-1,2-diphenyl-3,5-dioxopyrazolidine; 3,5-dioxo-1,2-diphenyl-4-n-butylpyrazolidine; flexazone; diphebuzol; fenibutazona; G-13871; R-3-ZON; Ambene (Merckle); Artrizin (Leo Pharm); Azolid (USV); Bizolin (Boehringer, Ing.); Butacote (Novartis); Butadion (Streuli); Butapirazol (Polfa); Butadiona (Miquel-Otsuka); Butatron (Sanofi); Butoz (Hamilton); Butazolidin (Novartis); Buzon (Knoll); Ecobutazone (Empire); Equipalazone (NCN); Exrheudon N (Optimed); Fenibutol (Atral); Intrabutazone (Organon); Intrazone (Arnolds); Mepha-Butazon (Mepha); Phenyzene (C-Vet); Robizone-V (Robins); Tevcodyne (Tevcon); Uzone (Douglas).
C19H20N2O2; mol wt 308.37.
C 74.00%, H 6.54%, N 9.08%, O 10.38%.

Description and references

Prepn: Stenzl, US 2562830 (1951 to Geigy); cf. GB 812449 (1959 to Geigy). Review of synthesis: Ullmanns Encyklop"adie der technischen Chemie vol. 13, 298 (1962). Physical properties and pharmacology: v. Rechenberg, Phenylbutazone (Edward Arnold, London, 1962) 197 pp. Acute toxicity: T. B. Gaines, R. E. Linder, Fundam. Appl. Toxicol. 7, 299 (1986). Soly data: Pulver et al., Schweiz. Med. Wochenschr. 86, 1080 (1956). Comprehensive description: S. L. Ali, Anal. Profiles Drug Subs. 11, 483-521 (1982). Review of hematological effects: G. A. Faich, Pharmacotherapy 7, 25 (1987).

Chemical structure

Properties

Crystals from ethanol, mp 105°. Soly in water at 22.5°: 0.7 mg/ml (also reported as 2.2 mg/ml). pK 4.5 (from uv in water), pK 4.89 (titration in 50% ethanol), pK 5.25 (titration in 80% 2-methoxyethanol). uv max (acid methanol): 239.5 nm (log ε 4.19).

Derivative

Sodium salt.

Nomenclature

CAS number: 129-18-0
GP-26872; Elmedal (Thiemann).
C19H19N2NaO2; mol wt 330.36.
C 69.08%, H 5.80%, N 8.48%, Na 6.96%, O 9.69%.

Properties

Crystals, freely sol in water. pH of aq solns ≈8.2.

Derivative

Calcium salt.

Nomenclature

Ticinil Calcico (De Angeli).
C38H36CaN4O4; mol wt 652.79.
C 69.92%, H 5.56%, Ca 6.14%, N 8.58%, O 9.80%.

Properties

LD50 in adult male, female rats (mg/kg): 1311, 647 orally (Gaines, Linder).

Derivative

Piperazine salt.

Nomenclature

Pyrazinobutazone; pyrasanone; Carudol (Fher).
C19H20N2O2.C4H10N2; mol wt 394.51.
C 70.02%, H 7.66%, N 14.20%, O 8.11%.

Properties

mp 140-141° (solidifies and remelts at ≈180°).

Derivative

2-Amino-2-thiazoline salt.

Nomenclature

CAS number: 54749-86-9
4-Butyl-1,2-diphenyl-3,5-pyrazolidinedione compd with 4,5-dihydro-2-thiazolamine (1:1); thiazolinobutazone; TZB; LAS-11871; Fordonal (Almirall).
C22H26N4O2S; mol wt 410.53.
C 64.36%, H 6.38%, N 13.65%, O 7.79%, S 7.81%.

Description and references

Prepn: J. Moragues et al., Arzneim.-Forsch. 24, 1785 (1974). Pharmacology: M. Márquez, D. J. Roberts, ibid. 1786, 1790; M. Colombo et al., ibid. 26, 1347 (1976).

Properties

White crystals, mp 164-166°. LD50 orally in rats, mice: 1425, 1650 mg/kg (Colombo).

Therapeutic Category

Anti-inflammatory.

Therapeutic Category (Veterinary)

Analgesic; anti-inflammatory.

Keywords

Anti-inflammatory (Nonsteroidal); Pyrazolones