Free radical scavenger; metabolite of antipyrine, q.v. Prepn: L. Knorr, Ann. 238, 137 (1887). Structural determn by NMR and IR: R. Jones et al., Tetrahedron 19, 1497 (1963); F.-D. H"oppner et al., J. Prakt. Chem. 318, 555 (1976). Crystal structure: F. Bechtel et al., Cryst. Struct. Commun. 3, 469 (1973). HPLC determn in urine: M. A. Mikati et al., J. Chromatogr. 433, 305 (1988). Anti-ischemic and radical scavenging actions: T. Watanabe et al., J. Pharmacol. Exp. Ther. 268, 1597 (1994).
In treatment of stroke.