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Application of mixtures of tartaric acid derivatives in resolution via supercritical fluid extraction
Author(s) -
Kmecz Ildikó,
Simándi Béla,
Székely Edit,
Lovász Judit,
Fogassy Elemér
Publication year - 2007
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20362
Subject(s) - chemistry , tartaric acid , diastereomer , enantiomer , molar ratio , resolution (logic) , supercritical fluid , chromatography , chiral resolution , solvent , extraction (chemistry) , salt (chemistry) , supercritical fluid chromatography , supercritical carbon dioxide , supercritical fluid extraction , organic chemistry , high performance liquid chromatography , catalysis , artificial intelligence , computer science , citric acid
Racemic N ‐methylamphetamine ( rac ‐MA) was resolved with 2R , 3R ‐tartaric acid (TA) and its derivatives ( O , O ′‐dibenzoyl‐( 2R , 3R )‐tartaric acid monohydrate (DBTA) and O , O ′‐di‐ p ‐toluoyl‐( 2R , 3R )‐tartaric acid (DPTTA)), individually and using them in different combinations. After partial diastereomeric salt formation, the free enantiomers were extracted by supercritical fluid extraction using carbon dioxide as solvent. DBTA and DPTTA are efficient resolving agents for rac ‐MA, the best chiral separation being obtained at a molar ratio of 0.25 resolving agent to racemic compound for both resolving agents (ee E = 82.5% and ee E = 57.9%, respectively). Compared with the two other acids, TA is practically unsuitable for enantiomer separation (ee E < 5%). Applying a mixture of one individually active and one ineffective acid in half the equivalent molar ratio, when the acids are in 1:1 ratio in the mixture, the resolution efficiency values obtained exceeded those obtained by using the components individually. Decreasing the molar ratio of resolving agent mixture to 0.25, at which the individual resolving agents give the best chiral separation, the obtained resolution efficiency values did not differ significantly from those expected. The outcome of the resolution process depended only on the amount of the individually active resolving agents in the mixture. Chirality, 2007. © 2007 Wiley‐Liss, Inc.