A convenient synthetic route to novel 7-substituted benzo[f]thieno[3,2-h]quinazoline and 8-substituted benzo[g,h]dithieno[2,3-e:3',2'-j]perimidine systems, bearing the fused pyrimidine ring, has been advanced. A com. available 5-bromopyrimidine was used as the starting material to obtain various polycyclic systems through the sequence of nucleophilic arom. substitution of hydrogen (the SNH reaction), Suzuki cross-coupling and oxidative photocyclization. Evidence for the structure of benzo[g,h]dithieno[2,3-e:3',2'-j]perimidines has been obtained by X-ray crystallog. anal. MO calcns. (DFT), as well as redox and optical measurements for all new compds. have been performed. The data show that the reported polycyclic systems have potential for use in org. electronic applications. The synthesis of the target compds. was achieved using 5-bromo-4-(2-thienyl)pyrimidine and (phenyl)boronic acids as starting materials
