Patent · US Expired

Method of resolution of two enantiomers by crystallization

US6022409A · kind A · utility

6Cited by
0References
19Claims
0Family size

Assignee

Inventors

Key dates

Filing dateOct 2, 1996
Grant dateFeb 8, 2000
Priority date
Expiry dateOct 2, 2016

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC07D233/74
  • WIPO fieldOrganic fine chemistry
  • WIPO sectorChemistry

Abstract

A method of optical enantiomer resolution by preferential crystallization involves entering, each time crystallization starts, the two-phase domain containing excess enantiomer and the saturated solution, and cooling according to a well-defined kinetic schedule. A racemic mixture of fine particle size is added to the mother liquors obtained after harvesting the crystals, the mother liquors then being heated to a temperature lower than that of homogenization of the solution so that excess enantiomer is present only in a solid state in equilibrium with the solution. Further cooling produces the other enantiomer and completes the cycle of operations which may then be carried out repetitively.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.