The formation of new C–C bonds is important in chemistry for the preparation of structurally complex products. A very elegant approach for the formation of new carbon-carbon bonds is through direct C–H activation. C–H functionalization allowed us to reach regioselectivity, since our substituted quinazolines have abundant reactive sites. Quinazolines are often a building block in natural sources as well as pharmaceutical substances and have a wide range of biological properties, which is why they are interesting for further exploration. In the master’s thesis we studied directed ruthenium/palladium double CH arylation of 2-substituted quinazolines 6. Both ruthenium(II)- and palladium(II)-catalysed reaction rates were investigated and optimized. in both metal-catalysed reaction steps, the effect of different catalysts, medium, base, ligand, additive, temperature, and the amount of reagents used were checked. With the final optimized reaction conditions of the ruthenium-catalysed step, the monoarylated products 10 were synthesized, purified and characterized in the case of the thiophene as well as the furan derivative in good yields (23-67%). The best conditions of the palladium-catalysed step also allowed us to synthesize, with subsequent purification and characterization of the final diarylated products 14 (26-52%). In the last part, we also checked the performance of the one-pot method, without the need to isolate the intermediate. It proved to be an equally appropriate and simpler synthesis protocol, as we achieved comparable yields of the performed reactions.