Compounds of formula (I), pharmaceutical compositions comprising compounds of formula (I) and methods of inhibiting Hsp 90 in a cell, treating or preventing a proliferation disorder in a mammal and treating cancer in a mammal comprising administering a compound of formula (I) to a patient or a cell.Variable R5is an optionally substituted heteroarylan optionally substituted 6 to 14-membered aryla bicyclic 9-member heterocycle optionally substituted at any substitutable nitrogen or carbon atomsor a substituent R18, defined herein. Ring A is an aryl or a heteroaryl optionally further substituted with one or more substituents in addition to R3. Substituent R3is defined herein.本發明係關於式(I)的化合物、包含式(I)的化合物之醫藥組成物、以及在細胞中抑制Hsp90、在哺乳類動物中治療或預防增生性失調症、和在哺乳類動物中治療癌症的方法,其包括將式(I)的化合物投藥至病患或細胞。變數R5係視需要經取代的雜芳基、視需要經取代的6至14員芳基、視需要在任何可取代的氮或碳原子上經取代的雙環狀9員雜環、或如本文中所定義的取代基R18。環A係需要進一步以一個或多個除了R3之外的取代基取代的芳基或雜芳基。取代基R3係如本文中所定義的。
