Disclosed herein are triazolopyridine compounds of general formula (I) which are Monopolar Spindle 1 kinase (Mps-1, also known as Tyrosine Threonine Kinase, TTK) inhibitors, in which R1, R2, R3, R4, and R5 are defined in the specification, to methods of preparing the compounds, to pharmaceutical compositions and combinations comprising the compounds, to the use of the compounds for manufacturing a pharmaceutical composition for the treatment or prophylaxis of proliferative diseases such as uncontrolled cell growth, proliferation and/or survival, an inappropriate cellular immune response, or an inappropriate cellular inflammatory response, as well as to intermediate compounds useful in the preparation of the compounds. In one embodiment the compound is 2-(4-methylpiperazin-1-yl)-N-[4-(2-{ [2-(trifluoromethyl)phenyl]amino} [1,2,4]triazolo[1,5-a]pyridin-6-yl)phenyl]acetamide.
