592608 Disclosed are 4-amino-pyrazolo[3,4-d]pyrimidine derivatives as represented by the general formula II-A-1, or a pharmaceutically acceptable salt thereof, wherein: X1 and X2 are N； R1 is hydrogen, -L-alkyl, -L-cycloalkyl, -L-alkylheterocyclyl, -L-heteroalkyl, or -L-heterocyclyl, each of which is unsubstituted or substituted by one or more independent R3 substituents； L is a bond, C=O, -C(=O)O-, -C(=O)N(R31)-, -S-, -S(O)-, -S(O)2-, -S(O)2N(R31)-, or -N(R31)-； E2 is H； each of R31 and R32 are independently H or unsubstituted alkyl； wherein heterocyclyl is a substituted or unsubstituted 3-, 4-, 5-, or 6- membered saturated or partially unsaturated ring containing one, two, or three heteroatoms independently selected from oxygen, nitrogen and sulfur； or to a bicyclic ring system containing up to 10 atoms including at least one heteroatom independently selected from oxygen, nitrogen, and sulfur wherein the ring containing the heteroatom is saturated； and wherein the remaining substituents are as defined herein. Representative compounds include 4-amino-1-(1-hydroxy-2-methyl-propan-2-yl)-3-(2-amino-1,3-benzoxazol-5-yl)-pyrazolo[3,4-d]pyrimidine. Also disclosed is a pharmaceutical composition which comprises a compound or pharmaceutically acceptable salt as defined above, and further comprising a pharmaceutical excipient, for inhibiting activity of a protein kinase and/or a lipid kinase present in a cell, such as mTor, and for the treatment of cancer, bone disorder, inflammatory disease, immune disease, nervous system disease, metabolic disease, respiratory disease, and cardiac disease.
