The present invention relates to compounds useful as inhibitors of protein kinases, particularly of JAK family kinases. The invention also provides pharmaceutically acceptable compositions comprising said compounds and methods of using the compositions in the treatment of various disease, conditions, or disorders.本發明係關於適合作為蛋白激酶、尤其JAK家族激酶抑制劑之化合物。本發明亦提供包含該等化合物之醫藥學上可接受之組合物及使用該等組合物治療各種疾病、病況或病症之方法。