The present invention relates to the use of novel pyrrolopyrazinyl urea derivatives of FormulaI,wherein the variables R1, R2, R3, R4, and R5are defined as described herein, which inhibit JAK and are useful for the treatment of auto-immune and inflammatory diseases.本發明係關於一種式I之新穎吡咯并吡基脲衍生物之用途,其中代號R1、R2、R3、R4及R5係如本文所述定義,該等衍生物抑制JAK且適用於治療自體免疫及發炎性疾病。