PROCESS FOR ISOLATION OF A MIXTURE OF RRRS AND SSSR CONFIGURATIONS OF NEBIVOLOL INTERMEDIATES

摘要

The invention discloses a process for isolation of a mixture of RRRS and SSSR configurations of nebivolol intermediates represented by formulae II and III respectively, which is optionally selected from one of the following two manners: (1) precipitation solvent is added to alcohol solvent comprising the mixture of RRRS, SSSR, RRSR and SSRS configurations of nebivolol intermediates represented by formula I, heating, cooling to precipitate crystals and filtrating; (2) the mixture of RRRS, SSSR, RRSR and SSRS configurations of nebivolol intermediates represented by formula I is added into the mixture solvent of alcohol solvent and precipitation solvent, heating, cooling to precipitate crystals and filtrating. In formulae I, II and III, X is H, C₁-C₆ alkyl or C₁-C₆ alkoxy, n is 1-5.