A series of [1,2,4]triazolo[1,5-a]pyrimidine-cored push-pull compounds, bearing ethynyl moieties, was effectively prepared using transition-metal-free strategy involving the direct C−H functionalization of [1,2,4]triazolo[1,5-a]pyrimidine scaffold with the Grignard-Iocich reagents (ethynylmagnesium bromides). The basic optical and electrochemical properties of the synthesized derivatives were studied and gave grounds to consider the obtained compounds as promising UV dyes with high quantum yields.