The invention relates to compounds of formula (I) and salts thereof wherein the substituents are as defined in the specification, the application of a compound of formula (I) in a process for the treatment of the human or animal body, in particular with regard to C-Met tyrosine kinase mediated disease; the use of a compound of formula (I) for manufacturing a medicament for the treatment of such diseases; pharmaceutical compositions comprising a compound of the formula (I), optionally in the presence of a combination partner; processes for the preparation of a compound of formula (I).