The invention provides compounds of formula (I):where the variables are defined in the specification, or a pharmaceutically-acceptable salt thereof, that are useful as JAK kinase inhibitors. The invention also provides pharmaceutical compositions comprising such compounds and methods of using such compounds to treat respiratory diseases.本發明提供適用作JAK激酶抑制劑之式(I)化合物:其中變數在本說明書中定義;或其醫藥學上可接受之鹽。本發明亦提供包含此等化合物之醫藥組合物及使用此等化合物治療呼吸道疾病之方法。