Method for separating enantiomers

Abstract

The method for separating enantiomers involves conducting achiral chromatography (ACh) of a non-racemic starting enantiomer mixture dissolved in a first solvent during the first cycle of separation, yielding a first product (F1ACh), which is the key enantiomer, and a second product (F2ACh), which is a mixture of both enantiomers. Subsequently, the second product (F2ACh), which is dissolved in an aliquot of the second solvent, is evaporated to dryness to obtain a fraction of the second mixture (F1CCh) enriched in the key enantiomer. Chiral chromatography (CCh) is conducted until the enantiomeric excess (ee) of the key enantiomer is equal to the enantiomeric excess (ee) of the key enantiomer in the starting enantiomeric mixture.The obtained enriched fraction of the second mixture (F1CCh) is evaporated to dryness and combined with a portion of the non-racemic starting mixture of enantiomers, dissolved in the first solvent and then a second separation cycle is carried out with a first step with achiral chromatography (ACh) identical to the first separation cycle and then a second step with chiral chromatography (CCh).