Title: Lofexidine
CAS Registry Number: 31036-80-3
CAS Name: 2-[1-(2,6-Dichlorophenoxy)ethyl]-4,5-dihydro-1
H-imidazole
Synonyms: 2-[1-(2,6-dichlorophenoxy)ethyl]-2-imidazoline
Molecular Formula: C11H12Cl2N2O
Molecular Weight: 259.13
Percent Composition: C 50.99%, H 4.67%, Cl 27.36%, N 10.81%, O 6.17%
Literature References: a2-Adrenoceptor agonist related structurally to clonidine,
q.v. Prepn of the HCl salt: H. Baganz, H. J. May,
ZA 6800850;
eidem, US 3966757 (1968, 1976 both to Nordmark); of the free base:
eidem, DE 1935479 (1971 to Nordmark),
C.A. 74, 87979 (1971). Pharmacological studies: J. Velly,
J. Pharmacol. 8, 351 (1977); B. Jarrot
et al., Biochem. Pharmacol. 28, 141 (1979). NMR data and cardiovascular effects: P. B. M. Timmermans, P. A. Van Zwieten,
Eur. J. Med. Chem. 15, 323 (1980). Hypotensive and sedative properties: P. Birch
et al., Br. J. Pharmacol. 68, 107 (1980). Effects in hypertension: N. D. Vlachakis
et al., Fed. Proc. 39, 4844 (1980). Series of articles on pharmacology, toxicology, clinical studies:
Arzneim.-Forsch. 32, 915-993 (1982). Toxicity studies: T. H. Tsai
et al., ibid. 955. Review of clinical trials in treatment of opiate withdrawal: J. Strang
et al., Am. J. Addict. 8, 337-348 (1999).
Properties: Crystals, mp 126-128°.
Melting point: mp 126-128°
Derivative Type: Hydrochloride
CAS Registry Number: 21498-08-8
Manufacturers' Codes: MDL-14042A; Ba-168
Trademarks: BritLofex (Britannia); Lofetensin (Nattermann)
Molecular Formula: C11H12Cl2N2O.HCl
Molecular Weight: 295.59
Percent Composition: C 44.70%, H 4.43%, Cl 35.98%, N 9.48%, O 5.41%
Properties: Crystals from ethanol/ether or 2-propanol, mp 221-223° (
U.S. patent); also reported as mp 230-232° (
Ger. patent). Very sol in water, ethanol. Slightly sol in 2-propanol. Practically insol in ether. LD50 in mice, rats, dogs (mg/kg): between 74-147 orally (all species); between 8-18 i.v. (all species) (Tsai).
Melting point: mp 221-223° (
U.S. patent); mp 230-232° (
Ger. patent)
Toxicity data: LD50 in mice, rats, dogs (mg/kg): between 74-147 orally (all species); between 8-18 i.v. (all species) (Tsai)
Therap-Cat: In treatment of opioid withdrawal symptoms; antihypertensive.
Keywords: Antihypertensive; Imidazole Derivatives.