METHOD OF TRAMADOL RACEMATES CLEAVAGE Russian patent published in 2002 - IPC

FIELD: pharmacy, chemical technology. SUBSTANCE: invention relates to method of cleavage of tramadol racemates. Tramadol hydrochloride that is (1RS, 2RS)-2-dimethylaminomethyl-1-(3-methoxyphenyl)-cyclo- -hexanol hydrochloride is a strong analgetic no causing, in contrast to opioids, the known adverse effects. Tramadol enantiomers shows interesting set of pharmacological properties that are distinct from that in tramadol racemate. Tramadol racemic salt, mainly hydrochloride, is converted to a base with L-tartaric acid in suitable solvent medium, usually organic solvent, preferably, in the presence of aliphatic C₁-C₅-alcohol and (-)-enantiomer of tramadol is separated by crystallization as a rule. (+)-Enantiomer of tramadol is isolated from mother precipitate solution obtained by precipitation with tartaric acid, base release and the following conversion to suitable salt but distinguishing from tartrate. Proposed method ensures to obtain enantiomers with constant high yield and high degree of purity. EFFECT: improved method of cleavage, enhanced purity, increased yield. 5 cl, 2 ex