β″-di-R-substituted fused thiophene (DCXFT4) compounds, and a method for making a compound of the formula (V): where each R is a C4 to C25 hydrocarbylene, the method including di-acylating tetra-bromo dithiophene (I); contacting the bromo-dithiophene compound (II) with a 2-mercaptoacetate to form cyclized fused thiophene (III); converting fused thiophene (III) to the corresponding diacid (IV); and decarboxylating the diacid (IV) to the fused thiophene (V), of the formulas as defined herein.