Process for preparing hemicalcium salt of (E)-7-[4-(4-fluorophenyl)-6-isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl](3R,5S)-3,5-dihydroxy-6-heptenoic acid

摘要

A method of preparation of the hemi-calcium salt of rosuvastatin of formula (I) consists in extracting an aqueous solution of the sodium or potassium salt of (E)-7-[4-(4-fluorophenyl)-6isopropyl-2-[methyl(methylsulfonyl)amino]pyrimidin-5-yl](3R,5S)-3,5-dihydroxy-6-heptenoic acid, with optional admixture of sodium or potassium hydroxide or other sodium or potassium salts having inorganic anions, with an organic solvent, incompletely miscible with water, selected from the series of R¹COOR², R¹COR² and R¹OH, wherein R¹ and R² independently represent hydrogen or a residue of a C₁-C₁₀ aliphatic hydrocarbon, C₆ aromatic hydrocarbon, C₅ or C₆cyclic hydrocarbon, or a combination of an aliphatic and aromatic or cyclic hydrocarbon, the extract being subsequently shaken with an aqueous solution of an inorganic or C₁-C₅ organic calcium salt, and the product of formula I is further isolated by cooling and/or adding an anti-solvent and filtration, and optionally, is converted into its amorphous form.