The invention relates to compounds of formula (I) and salts thereof: wherein the substituents are as defined in the specification; a compound of formula (I) for use in the treatment of the human or animal body, in particular with regard to c-Met tyrosine kinase mediated diseases or conditions; 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, and processes for the preparation of a compound of formula (I).