The invention relates to compounds of formula (I) wherein X and R<1> to R<5> have the meaning as cited in the description and the claims. Said compounds are useful as protein kinase inhibitors, especially inhibitors of Itk or PI3K, for the treatment or prophylaxis of immunological, inflammatory or allergic disorders. The invention also relates to pharmaceutical compositions including said compounds, the preparation of such compounds as well as the production of and use as medicaments.