Described herein are pyrrolo[2,3-d]pyrimidine compounds, their use as Janus Kinase (JAK) inhibitors, pharmaceutical compositions containing these compounds, and methods for their preparation.本發明揭露吡咯並[2,3-d]嘧啶化合物類、彼等作為Janus激酶(JAK)抑制劑之用途、含有該等化合物之醫藥組成物及製備該等化合物之方法。