(-)-N-METHYLEPHEDRINE

Description

The Chinese plant 'Ma-Huang' contains this alkaloid, first isolated by Smith. According to Read, the name 'Ma-Huang' is the name for various Ephedra species but the material principally used in China is E. sinica Stapf. (Syn. E. j7ava Porter Smith, E. Mahuang Liu). It has subsequently been discovered in European species, notably E. helvetica C. A. Meyer and E. distachya Linn. The alkaloid crystallizes in stout, colourless needles and has [α]_D - 29.2° (MeOH). It yields several crystalline salts and derivatives: hydrochloride, m.p. 188-9°C; [α]²⁰_D - 29.8° (H20); oxalate, m.p. 187°C; aurichloride, m.p. 128-9°C; picrate, m.p. 144°C and the methiodide, m.p. 212-3°C; [α]_D - 21.8° (H20).

Chemical properties

White crystals or adhering crystalline powder

The Uses of (-)-N-METHYLEPHEDRINE

adrenergic agonist, analeptic

The Uses of (-)-N-METHYLEPHEDRINE

Used in conjunction with LiAlH4 for chiral reductions

Definition

ChEBI: (1R,2S)-2-(dimethylamino)-1-phenyl-1-propanol is an alkylbenzene.

Purification Methods

N-Methylephedrine has been recrystallised from Et2O, pet ether, of aqueous EtOH or aqueous MeOH and has been distilled under reduced pressure. [Smith J Chem Soc 2056 1927, Tanaka & Sugawa Yakugaku Zasshi (J Pharm Soc Japan) 72 1548 1952 (Chem Abstr 47 8682 1953), Takamatsu Yakugaku Zasshi (J Pharm Soc Japan) 76 1227 1956, Chem Abstr 51 4304 1957.] The hydrochloride has m 192-193o and [] D (c 5,H2O)[Prelog & Hüfliger Helv Chim Acta 33 2021 1950].20+30o [Beilstein 13 IV 1884.]

References

Smith., J. Chern. Soc., 2056 (1927)
Smith., ibid, 51 (1928)
Smith., ibid, 2755 (1929)
Wolfes., Arch. Pharrn., 268,327 (1930)
Preparation:
Nagai., J. Pharrn. Soc., Japan, No. 120, 109 (1892)
Nagai, Kanao., ibid, 48, 145 (1928)