Pyrazole derivatives for treating conditions mediated by activation of the adenosine a2b or a3 receptor

Compounds of formula (I) in free or salt form, wherein R1, R2, R3 and R4 have the meanings as indicated in the specification, are useful for treating a condition mediated by activation of the adenosine Alb receptor or the adenosine A3 receptor, particularly an inflammatory or obstructive airways disease. Pharmaceutical compositions that contain the compounds and processes for preparing the compounds are also described.