Patent ID: 7563911

Claim:
An improved process for the preparation of amorphous atorvastatin calcium, [R—(R*,R*)]-2-(4-Fluorophenyl)-β,δ-dihydroxy-5-(1-methylethyl)-3-phenyl-4-[(phenylamino)carbonyl]1H-pyrrole-1-heptanoic acid calcium salt (2:1) having formula comprising: (a) obtaining a reaction mixture of (2R-trans)-5-(4-fluorophenyl)-2-( 1-methyl ethyl)-N,4-diphenyl-1-[2-(tetrahydro-4-hydroxy-6-oxo-2H-pyran-2-yl)ethyl]-1-H-pyrrole-3-carboxamide of formula: and an aqueous solution of alkali or alkaline earth metal hydroxide; (b) extracting reaction product of step (a) in an organic solvent that is methylene chloride; (c) adding an anti-solvent that is diisopropyl ether to the extracted product of step (b); and (d) isolating the amorphous atorvastatin calcium after step (c) followed by drying at 45-50° C.