Synthesis and Reactivity of Dithienopyrazines**

Heteroacenes developed to widely used building blocks in organic semiconductors for application electronics due their tunable structures and properties concomitant with inherent stability. Here, we report efficient preparation investigation of so far unknown heterotriacenes, basic anti- syn-dithienopyrazine 5 6. The comparison the two isomers respect electronic follow-up reactions gives insights into structure-property -reactivity relationships. Examples transition metal-catalyzed C−C cross-coupling corresponding halogenated derivatives show practical impact extended π-conjugated systems applied optoelectronic devices.