Cyclopropanecarboxylate esters of purine analogues

Cydopropanecarboxylate esters of purine analogues, method of making and using the same for treating herpes virus infections and tumors are disclosed. In an embodiment of the invention, the compound of the invention may be used for treating cancer A cancer patient may be first administered a vector, such as an adenovector, comprising a DNA insert encoding HSV thymidme kinase, said vector expressing HSV thymidine kinase in the tumor cells of the subject, followed by administration of the compound of the invention. In another aspect the invention relates to use of a compound or a pharmaceutically acceptable salt, a solvate or hydrate, a prodrug, or a metabolite thereof as aforementioned in the manufacture of a medicament for treating herpes virus infection. The medicament may be for treating herpes simplex virus infection, herpes zoster infection, or cytomegalovirus infection.