Derivatives of 8-substituted xanthines

A compound of formula I:

• wherein:
• R is hydrogen or is selected from the group consisting of (C1-5)alkyl, halo(C1-8)alkyl, (C3-8)cycloalkyl, (C3-8)cycloalkyl(C1-8)alkyl-, (C3-5)alkenyl and (C3-5)alkynyl, each substituted or unsubstituted;
• R1 and R2 are each independently selected from the group consisting of hydrogen, substituted or unsubstituted (C1-8)alkyl, halo(C1-8)alkyl, (C3-8)alkenyl, (C3-8)alkenyl(C1-8)alkyl, (C3-8)alkynyl, (C3-8)alkynyl(C1-8)alkyl, (C1-8)alkoxy, (C3-8)cycloalkyl, (C3-8)cycloalkyl(C1-8)alkyl, (C4-10)heterocyclyl, (C4-10)heterocyclyl(C1-8)alkyl, (C6-10)aryl, (C6-10)aryloxy, (C6-10)aryl(C1-8)alkyl-, (C5-10)heteroaryl and (C5-10)heteroaryl(C1-8)alkyl-;
• L1 is a linker selected from the group consisting of substituted or unsubstituted——NRo—C(O)—, —NCH3—C(O)—, —C(O)NRo—, —C(O)NCH3—, —NRoC(O)CH2—, —NRoC(O)CH2CH2—, —C(O)NRoCH2—, —C(O)NRoCH2CH2—, —C(O)CH2NRo—, —C(O)CH2CH2NRo—, —CH2NRoC(O)—, —CH2CH2NRoC(O)—, —CH2C(O)NRo—, —CH2CH2C(O)NRo—, —NRoCH2C(O)—, and —NRoCH2CH2C(O)—, wherein each Ro is independently hydrogen or substituted or unsubstituted (C1-4)alkyl, (C1-4)alkylC(O)—, (C6-10)arylC(O)— and (C5-10)heteroarylC(O)—;
• Z is a 5-14 member substituted or unsubstituted heteroaryl ring selected from the group consisting of benzo[b]furan, benzo[b]thiophene, benzimidazole, imidazo[4,5-c]pyridine, quinazoline, thieno[2,3-c]pyridine, thieno[3,2-]pyridine, thieno[2,3-b]pyridine, indolizine, imidazo[1,2a]pyridine, quinoline, isoquinoline, phthalazine, quinoxaline, naphthyridine, quinolizine, indole, isoindole, indazole, indoline, benzoxazole, benzopyrazole, benzothiazole, imidazo[1,5-a]pyridine, pyrazolo[1,5-a]pyridine, pteridine, purine, carbazole, and acridine;
• Z1 is a 5-14 member substituted or unsubstituted aryl or heteroaryl ring;
• where n is 1 or 2;
• or
• a pharmaceutically acceptable salt thereof.