Download full text in PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... Synthetic approaches to 2-[(bis-t-butoxycarbonyl)amino]-9-hydroxy-6-methoxypurine ( ) and 9-hydroxy-6-phthalimidopurine ( ) are described. These 9-hydroxypurines are useful intermediates in the synthesis of 9-alkoxyguanine and 9-alkoxyadenine derivatives as potential antiviral ...