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. ... A method for the combinatorial synthesis of 2,9-substituted purines using a Mitsunobu reaction to alkylate the N-9 position and an amination reaction to install amines at the C-2 position has been developed. ... A method for the combinatorial synthesis of 2,9-substituted purines is ...