An efficient protocol for the syntheses of diverse 2, 6, 7-and 2, 6, 9-trisubstituted purines is reported starting from the guanine precursor, 2-amino-6-chloropurine nucleoside through subsequent regioselective, high yielding Mitsunobu coupling and nucleophilic substitutions at C6 with versatile primary and secondary amines. A wide range of 2, 6, 7-and 2, 6, 9- trisubstituted purines were accessible in good to excellent yields with remarkable ...