PROCESS FOR PREPARING 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.