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Environmentally benign chiral resolution of trans - 1,2 - cyclohexanediol by two - step supercritical fluid extraction / Edit Szekely in Industrial & engineering chemistry research, Vol. 49 N° 19 (Octobre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9349–9354 Titre : Environmentally benign chiral resolution of trans - 1,2 - cyclohexanediol by two - step supercritical fluid extraction Type de document : texte imprimé Auteurs : Edit Szekely, Auteur ; Gyorgy Bansaghi, Auteur ; Paul Thorey, Auteur Année de publication : 2010 Article en page(s) : pp. 9349–9354 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cyclohexanediol  Supercritical  fluid  extraction Résumé : A racemic mixture of trans-1,2-cyclohexanediol (CHD) is reacted with S,S- or R,R-tartaric acid in ethanol with a 0.5 or higher molar ratio of resolving agent to racemic CHD. The tartaric acid (TA) forms a diastereomeric cocrystal with only one of the enantiomers; the other enantiomer remains unreacted at any molar ratio. The unreacted mixture of enantiomers is recovered from the sample by supercritical fluid extraction at 20 MPa and 33 °C. A subsequent extraction is then performed at 20 MPa and at least 73 °C. During this second extraction step, the diastereomeric cocrystal is decomposed in situ. Both enantiomers are recovered in nearly 50−50% yield with enantiomeric excess values of 65−90%. The mixtures of enantiomerss rich in S,S-CHD and R,R-CHD are then reacted with S,S-TA and R,R-TA, respectively, and the procedure is repeated. In two resolution steps, both enantiomers of CHD were produced in quantitative yields in a purity of ee > 99%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101107u [article] Environmentally benign chiral resolution of trans - 1,2 - cyclohexanediol by two - step supercritical fluid extraction [texte imprimé] / Edit Szekely, Auteur ; Gyorgy Bansaghi, Auteur ; Paul Thorey, Auteur . - 2010 . - pp. 9349–9354. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 19 (Octobre 2010) . - pp. 9349–9354 Mots-clés : Cyclohexanediol  Supercritical  fluid  extraction Résumé : A racemic mixture of trans-1,2-cyclohexanediol (CHD) is reacted with S,S- or R,R-tartaric acid in ethanol with a 0.5 or higher molar ratio of resolving agent to racemic CHD. The tartaric acid (TA) forms a diastereomeric cocrystal with only one of the enantiomers; the other enantiomer remains unreacted at any molar ratio. The unreacted mixture of enantiomers is recovered from the sample by supercritical fluid extraction at 20 MPa and 33 °C. A subsequent extraction is then performed at 20 MPa and at least 73 °C. During this second extraction step, the diastereomeric cocrystal is decomposed in situ. Both enantiomers are recovered in nearly 50−50% yield with enantiomeric excess values of 65−90%. The mixtures of enantiomerss rich in S,S-CHD and R,R-CHD are then reacted with S,S-TA and R,R-TA, respectively, and the procedure is repeated. In two resolution steps, both enantiomers of CHD were produced in quantitative yields in a purity of ee > 99%. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101107u