The invention relates to compounds of formula (I)wherein AA, R2 to R7 and X1 to X3 have the meaning as cited in the description and the claims. Said compounds are useful as selective inhibitors of JAK3 over JAK2 for the treatment or prophylaxis of immunological, inflammatory, autoimmune, allergic disorders, and immunologically-mediated diseases. The invention also relates to pharmaceutical compositions including said compounds, the preparation of such compounds as well as the use as medicaments.