Method for preparing unformed Atorvastatin calcium by using crystalline Atorvastatin sodium

• Main Authors: CHEN ZHIRONG, CHEN ZHENGXU, JIN FANGFEI
• Format: Patent
• Language: Chinese; English
• Published: 26.12.2007
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

This invention discloses a method for preparing amorphous atorvastatin calcium from crystalline atorvastatin sodium. The method comprises: (1) adding crystalline atorvastatin sodium 1 part into a reactor with stirrer, adding water-saturated n-butanol, isobutanol, butanone, 2-methyltetrahydrofuran or ethyl acetate 30-60 parts, and stirring to obtain a suspension; (2) dropping 3-10% calcium acetate aqueous solution 2.5-5 parts, and stirring for 0.5 -3 h after dropping; (3) standing, separating the water layer, washing the upper layer solution with water 5-10 parts for 2-3 times, and separating the water layer; (4) vacuum-concentrating the upper layer solution to remove the solvent and obtain amorphous atorvastatin calcium. The method has such advantages as no need for filtration, and high yield of amorphous atorvastatin calcium.