4012. Feprazone

Nomenclature

CAS number: 30748-29-9
4-(3-Methyl-2-butenyl)-1,2-diphenyl-3,5-pyrazolidinedione; 4-prenyl-1,2-diphenyl-3,5-pyrazolidinedione; 4-prenyl-1,2-diphenyl-3,5-dioxopyrazolidine; 4-(β-isoamylenyl)-1,2-diphenyl-3,5-pyrazolidinedione; 4-(2-isopentenyl)-1,2-diphenyl-3,5-pyrazolidinedione; phenylprenazone; prenazone; DA-2370; Analud (Unifa); Methrazone (Boehringer, Ing.); Zepelin (De Angeli).
C20H20N2O2; mol wt 320.39.
C 74.98%, H 6.29%, N 8.74%, O 9.99%.

Description and references

Non-steroidal anti-inflammatory drug. Prepn: S. Casadio, G. Pala, DE 2031238; eidem, US 3703528 (1971, 1972 both to Ist. De Angeli); Casadio et al., Arzneim.-Forsch. 22, 171 (1972). Series of articles on physical-chemical data, pharmacology, toxicology and clinical studies: ibid. 174-281. Toxicity data: C. Bianchi, G. Bonardi, ibid. 196.

Chemical structure

Properties

Fine, white odorless and tasteless crystalline powder, mp 156.5° (ethanol). Very sol in acetone, chloroform, DMF; sparingly sol in acetonitrile, benzene, 10% NaOH. Slightly sol in ether, methanol, ethanol, cyclohexane. Practically insol in 10% HCl, 10% acetic acid, water. uv max (ethanol): 246 nm (log ε 4.19); (pH 9-12 buffer): 264 nm (log ε 4.322-4.326). pKa 5.09 ± 0.07. LD50 in male mice, rats (mg/kg): 408.8, 386.4 i.p.; 1067, >2000 orally (Bianchi, Bonardi).

Therapeutic Category

Anti-inflammatory.

Keywords

Anti-inflammatory (Nonsteroidal); Pyrazolones