Patent ID: 7550596

Claim:
A method of obtaining Ethyl(3R,5S,6E)-7-[2-cyclopropyl-4-(4-fluorophenyl)quinoline-3-yl]-3,5-dihydroxy-6-heptenoate comprising separating Ethyl(3R,5S,6E)-7-[2-cyclopropyl-4-(4-fluorophenyl)quinoline-3-yl]-3,5-dihydroxy-6-heptenoate from a solution which comprises a mixture of optical isomers of Ethyl 6E-7-[2-cyclopropyl-4-(4-fluorophenyl)quinoline-3-yl]-3,5-dihydroxy-6-heptenoate by means of liquid chromatography using a packing material comprising a carrier and a polysaccharide derivative carried on the carrier, wherein the polysaccharide derivative, wherein at least a part of hydrogen atoms of hydroxyl and amino groups of the polysaccharide are substituted by one or two or more kinds of substituents each represented by the following general formula (1) or (2), wherein in both formulae (1) and (2), at least one of R 1 to R 5 represents a linear or branched alkyl group having 3 to 8 carbon atoms, and the others each represent a substituent selected from hydrogen, halogen, or an alkyl group.