Pharmaceutically active compounds having a tricyclic pyrazolotriazolopyrimidine ring structure and methods of use

1. A compound of any one of the following Formula IX or X:

wherein:

R 1 is selected from the group consisting of hydrogen, C 1-6 alkylamino, di(C 1-6 ) alkylamino, and C 1-6 alkylthio;

R 2 is selected from optionally substituted C 1-6 alkyl and optionally substituted C 7-12 aralkyl;

R 3 is selected from the group consisting of optionally substituted a C 1-6 alkyl, optionally substituted C 7-12 aralkyl, and optionally substituted C 2-6 alkanoyl;

E is O or N—C 1-6 alkyl; and pharmaceutically acceptable salt thereof.

2. A compound that is:

4-(5-Amino-7-phenethyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-phenol;

2-(4-Chloro-phenyl)-7-phenethyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine;

2-(4-Ethoxy-phenyl)-7-phenethyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine; [4-(5-Amino-7-phenethyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-phenoxy]-acetic acid ethyl ester;

[4-(5-Amino-7-phenethyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-phenoxy]-acetic acid;

2-[4-(5-Amino-7-phenethyl-7H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-2-yl)-phenoxy]-N-(4-iodo-phenyl)-acetamide;

N9-Ethyl-2-furan-2-yl-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine-5,9-diamine;

N9-Ethyl-2-furan-2-yl-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine-5,9-diamine hydrochloride salt;

2-Furan-2-yl-N-9-(4-methoxy-phenyl)-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidine-5,9-diamine;

2-Furan-2-yl-8-methyl-9-(4-methyl-piperazin-1-yl)-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine;

2-Furan-2-yl-8-methyl-9-(4-methyl-piperazin-1-yl)-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine dihydrochloride salt;

2-Furan-2-yl-8-methyl-9-methylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine;

2-Furan-2-yl-8-methyl-9-propylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine;

2-Furan-2-yl-9-methylsulfanyl-8-(3-phenyl-propyl)-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine;

1-(9-Ethylamino-2-furan-2-yl-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-3-(4-methoxy-phenyl)-urea;

1-(9-Ethylamino-2-furan-2-yl-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-3-(4-methoxy-phenyl)-urea hydrochloride salt;

1-[2-Furan-2-yl-8-methyl-9-(4-methyl-piperazin-1-yl)-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyimidin-5-yl]-3-(4-methoxy-phenyl)-urea;

1-(2-Furan-2-yl-8-methyl-9-methylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-3-(4-methoxy-phenyl)-urea;

N-(2-Furan-2-yl-8-methyl-9-methylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-2-(4-methoxy-phenyl)-acetamide;

N-(2-Furan-2-yl-8-methyl-9-methylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-2-(4-isobutyl-phenyl)-acetamide;

2-Benzo[1,3]dioxol-5-yl-N-(2-furan-2-yl-8-methyl-9-methylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-acetamide;

2-Benzo[1,3]dioxol-5-yl-N-(9-ethylamino-2-furan-2-yl-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-yl)-acetamide;

4-(5-Amino-2-furan-2-yl-8-methyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-9-ylamino)-phenol;

8-Methyl-2-[5-(4-methyl-piperazin-1-ylmethyl)-furan-2-yl]-9-methylsulfanyl-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine;

8-Methyl-9-methylsulfanyl-2-(5-morpholin-4-ylmethyl-furan-2-yl)-8H-pyrazolo[4,3-e][1,2,4]triazolo[1,5-c]pyrimidin-5-ylamine; or a pharmaceutically acceptable salt thereof.

3. A pharmaceutical composition comprising a pharmaceutically acceptable carrier and one or more compounds of any one of claims 1 or 2 .