Fused tricyclic analogues of guanosine for treating tumors

摘要

Fused tri-heterocyclic compounds of formula: <CHEM> R1 is H or alkyl; R2 is H, alkyl, alkenyl, aryl, heteroaryl, cyclyl, or heterocyclyl; R3 and R4, independently, is H, alkyl, alkenyl, aryl, heteroaryl, cyclyl, heterocyclyl, or (CR<a>R<b>)mX(CR<c>R<d>)nY; in which X is a bond, O, S, or NR<e>; Y is alkoxy, aryloxy, heteroaryloxy, OC(O)R<e>, C(O)R<e>, N(R<e>R<e>'), NR<e>C(O)R<e>', S(O)2R<e>, or SR<e>; each of m and n, independently, is 1, 2, 3, 4, or 5; each of R<a>, R<b>, R<c>, R<d>, R<e>, and R<e'>, independently, is H, alkyl, aryl, heteroaryl, cyclyl, or heterocyclyl; and R5 is H or halogen.