Patent ID: 6949644

Claim:
A method of preparing a 2,6,9-substituted purine compound having the Formula I: wherein: R 1 and R 2 are independently selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl and heterocyclyl; R 3 is hydrogen and R 4 is selected from the group consisting of alkyl, substituted alkyl, cycloalkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl and heterocyclyl or R 3 and R 4 when taken together with the nitrogen and carbon atoms to which they are respectively attached form an optionally substituted saturated heterocyclic ring; the method comprising: a) oxidizing a resin-bound compound of Formula II wherein: R 1 and R 2 are as defined above and n is 0 or 1; to provide a resin-bound compound of Formula III wherein R 1 , R 2 and n are as defined above; b) reacting the compound of Formula III with an amine of Formula IV NR 3 R 4 IV wherein R 3 and R 4 as defined above, to provide a resin-bound compound of Formula V wherein R 1 , R 2 , R 3 and R 4 are as defined above; and c) cleaving the resin-bound compound of Formula V from the resin to provide the substituted purine compounds of Formula I.