Process for isolating the antiviral agent [1S-(1alpha, 3alpha, 4beta)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-2-methylenecyclopentyl]-6H-purin-6-one

摘要

The invention refers to a method for isolating entecavir or an entecavir intermediate from a diluted mixture, the diluted mixture comprising entecavir and water or a mixture comprising an entecavir intermediate and other process reagents comprising:
(a) adsorbing the diluted mixture onto a hydrophobic resin bed;
(b) washing the resin bed with water to remove salt; and
(c) eluting the entecavir or entecavir intermediate from the resin bed with an organic solvent.