2345. Clemastine

Nomenclature

CAS number: 15686-51-8
(2R)-2-[2-[(1R)-1-(4-Chlorophenyl)-1-phenylethoxy]ethyl]-1-methylpyrrolidine; (+)-2-[2-[(p-chloro-α-methyl-α-phenylbenzyl)oxy]ethyl]-1-methylpyrrolidine; 1-methyl-2-[2-(α-methyl-p-chlorobenzhydryloxy)ethyl]pyrrolidine; 1-methyl-2-[2-(methyl-p-chlorodiphenylmethyloxy)ethyl]pyrrolidine; meclastine.
C21H26ClNO; mol wt 343.89.
C 73.34%, H 7.62%, Cl 10.31%, N 4.07%, O 4.65%.

Description and references

Ethanolamine antihistamine. Prepn: GB 942152 (1963 to Sandoz). Synthesis and abs config: A. Ebn"other, H. P. Weber, Helv. Chim. Acta 59, 2462 (1976). Pharmacology and toxicology of the hydrogen fumarate: Weidmann et al., Boll. Chim. Farm. 106, 467 (1967). HPLC determn in plasma: V. Horváth et al., J. Chromatogr. B 816, 153 (2005). Pharmacology in dogs: H. Hansson et al., Vet. Dermatol. 15, 152 (2004). Clinical trials in the common cold: J. M. Gwaltney, Jr. et al., Clin. Infect. Dis. 22, 656 (1996); R. B. Turner et al., ibid. 25, 824 (1997).

Chemical structure

Properties

Free base, bp0.02 154°. nD22 1.5582. [α]D20 +33.6° (ethanol).

Derivative

Hydrogen fumarate.

Nomenclature

CAS number: 14976-57-9
HS-592; Alphamin (SS Pharm.); Anhistan (Nippon Zoki); Kinotomin (Toa Eiyo); Lecasol (Kaken); Marsthine (Towa); Masletine (Shioe); Piloral (Nippon Kayaku); Tavegil (Novartis); Tavegyl (Novartis); Tavist (Novartis).
C25H30ClNO5; mol wt 459.96.
C 65.28%, H 6.57%, Cl 7.71%, N 3.05%, O 17.39%.

Properties

Faintly yellow crystalline solid. mp 177-178°. Very slightly sol in water; sparingly sol in alcohol. [α]D21 +16.9° (methanol). LD50 in mice, rats (mg/kg): 730, 3550 orally; 43, 82 i.v. (Weimann).

Therapeutic Category

Antihistaminic.

Therapeutic Category (Veterinary)

Antihistaminic.

Keywords

Antihistaminic; Aminoalkylethers