Method for the preparation of high-purity pharmaceutical intermediates

摘要

The disclosure relates to a method for the preparation of rosuvastatin tert-tertbutylammonium (TBA) salt of the formula (III) which is an intermediate useful in the manufacture of (+)-7-[4-(4-fluorophenyl)-6-isopropyl-2-(methanesulfonyl-methyl-amino)-pyrimidin-5-yl]-(3R,5S)-dihydroxy-hept-6-enoic acid, wherein the method comprises reacting a rosuvastatin ester of the formula (II) having solid crystalline form where in the formula (II) R represents methyl, ethyl or tert-butyl using a polar solvent, with 1.5 to 5 molar equivalents, of tert-butylamine in aqueous solution at a temperature between 10 °C and the boiling point of the solvent. Polymorphs of said intermediate, methods for preparation thereof and use thereof are also disclosed.