US 7,541,460 B2
Process for preparing the antiviral agent [1S-(1alpha, 3alpha, 4beta)]-2-amino-1,9-dihydro-9-[4-hydroxy-3-(hydroxymethyl)-3-methylenecyclopentyl]-6H-purin-6-one
Yeung Yu Chan, Kendall Park, N.J. (US); and Sushil K. Rijhwani, Robbinsville, N.J. (US)
Assigned to Bristol-Myers Squibb Company, Princeton, N.J. (US)
Filed on Dec. 19, 2005, as Appl. No. 11/311,194.
Application 11/311194 is a division of application No. 10/734012, filed on Dec. 11, 2003, granted, now 7,034,152.
Claims priority of provisional application 60/432549, filed on Dec. 11, 2002.
Prior Publication US 2006/0106215 A1, May 18, 2006
Int. Cl. C07D 473/18 (2006.01); C07D 473/40 (2006.01); C07F 7/08 (2006.01); C07F 7/10 (2006.01); C07F 7/18 (2006.01)
U.S. Cl. 544—276 2 Claims
 
1. 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.