Optically pure vinsyremonoestere of optically active alkanol amines, processes for the preparation of such optically pure ester and the use thereof for the manufacture of optically pure alkanolamines

摘要

For the analytical and preparative separation of the optical isomers of optically active alkanolamines into their optically pure antipodes a new resolution method is presented which involves an ester formation of the alkanolamines with optically pure and symmetrically O,O disubstituted (R,R)- or (S,S)-tartaric acids. The derivitization reactions are carried out in aprotic solvents and the primary and secondary functions are blocked via ion-pair formations with strong acids, e.g. dichloroacetic acid. The tartaric acid anhydrides are predominantly used as reagents but other ester formation methods are also practicable. The mixture of the diastereomeric alkanolamine tartaric acid monoesters are separable into their optically active and pure isomers by various chromotographic separation techniques, e.g. straight or reverse phase LC, but also by extraction methods e.g. Soxhlet extraction. The optically pure parent alkanolamine isomers can be obtained by ester hydrolysis, with high yield, from the optically pure fractions of the alkanolamine tartaric acid monoesters.