5329. Labetalol

Nomenclature

CAS number: 36894-69-6
2-Hydroxy-5-[1-hydroxy-2-[(1-methyl-3-phenylpropyl)amino]ethyl]benzamide; 5-[1-hydroxy-2-[(1-methyl-3-phenylpropyl)amino]ethyl]salicylamide; ibidomide.
C19H24N2O3; mol wt 328.41.
C 69.49%, H 7.37%, N 8.53%, O 14.62%.

Description and references

Specific competitive antagonist at both α- and β-adrenergic receptor sites. Prepn: L. H. Lunts, D. T. Collin, DE 2032642; eidem, US 4012444 (1971, 1977 both to Allen & Hanburys). Synthesis of labetalol and enantiomers: J. E. Clifton et al., J. Med. Chem. 25, 670 (1982); and comparison of cardiovascular properties: E. H. Gold et al., ibid. 1363. Abs config of dilevalol: P. Murray-Rust et al., Acta Crystallogr. C40, 825 (1984). Adrenoceptor blocking properties: E. J. Sybertz et al., J. Pharmacol. Exp. Ther. 218, 435 (1981). HPLC determn in serum or plasma: T. F. Woodman, B. Johnson, Ther. Drug Monit. 3, 371 (1981). Metabolism in animals and man: R. Hopkins et al., Biochem. Soc. Trans. 4, 726 (1976). Toxicity: K. Shimpo et al., Hokkaido Igaku Zasshi 53, 15 (l978), C.A. 90, 66465v (1974). Review of pharmacology: R. Donnelly, G. J. A. Macphee, Clin. Pharmacokinet. 21, 95-109 (1991); of therapeutic applications in hypertension and ischemic heart disease: K. L. Goa et al., Drugs 37, 583-627 (1989).

Chemical structure

Derivative

Hydrochloride.

Nomenclature

CAS number: 32780-64-6
AH-5158A; Sch-15719W; Amipress (Dox-Al); Ipolab (Finmedical); Labelol (ELEA); Labrocol (Lagap); Normodyne (Schering); Presdate (Alfa); Pressalolo (Locatelli); Trandate (Allen & Hanburys).
C19H24N2O3.HCl; mol wt 364.87.
C 62.54%, H 6.91%, N 7.68%, O 13.15%, Cl 9.72%.

Properties

White crystalline solid from ethanol-ethyl acetate, mp 187-189°. Sol in water, ethanol. Insol in ether, chloroform. LD50 in male, female mice, male, female rats (mg/kg): 114, 120, 113, 107 i.p.; 47, 54, 60, 53 i.v.; 1450, 1800, 4550, 4000 orally (Shimpo).

Derivative

(R,R)-Form hydrochloride.

Nomenclature

CAS number: 75659-08-4; 75659-07-3 (free base)
Dilevalol hydrochloride; Sch-19927.

Properties

Polymorphic crystals from ethanol, mp 133-134° (dec); mp 192-193.5° (dec). [α]D26 30.6° (c = 1.0 in ethanol).

Therapeutic Category

Antihypertensive.

Keywords

α-Adrenergic Blocker; β-Adrenergic Blocker; Antihypertensive; Arylethanolamine Derivatives