TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises (a) halogenating 2,3-thiophenedicarboxaldehyde diacetal by lithiation with alkyl lithium, lithium diisopropylamide or another lithiation reagent, and then reacting with a halogenation agent to obtain 5-halogenated 2,3-thiophenedicarboxaldehyde diacetal, where the halogenation agent is N-chlorosuccinimide, carbon tetrachloride, N-bromosuccinimide, carbon tetrabromide, N-iodosuccinimide, iodine chloride or elemental iodine; either (b) deprotecting 5-halogenated 2,3-thiophenedicarboxaldehyde diacetal under acidic conditions to the corresponding dialdehyde, and then condensing with a cyclic 1,4-diketone, preferably 1,4-cyclohexadione, 1,4-dihydroxynaphthalene or its higher analogues, to obtain quinone of the dihalogenated acenodithiophene, (c) treating the quinone of the dihalogenated acenodithiophene with silylethynyl lithium, followed by hydrolysis, e.g. with diluted hydrochloric acid to obtain a dihalogenated diol intermediate, (d) introducing heteroaryl groups in the dihalogenated diol intermediate by cross-coupling the intermediate with a corresponding heteroaryl boronic acid, boronic ester, stannane, zinc halide or magnesium halide, in the presence of a nickel or palladium complex as catalyst, to obtain a heteroaryl extended diol and (e) aromatizing the heteroaryl extended diol using a reducing agent under acidic conditions to obtain a terminally substituted heteroaryl acenodithiophene, or (f) reacting the 5-halogenated 2,3-thiophenedicarbox-aldehyde diacetal in a cross-coupling reaction with the corresponding heteroaryl boronic acid, boronic ester, stannane, zinc halide or magnesium halide, in the presence of a nickel or palladium complex as catalyst, deprotecting the obtained product and condensing with the cyclic 1,4-diketone, followed by treating with silylethynyl lithium and hydrolyzing, e.g. with diluted hydrochloric acid to obtain a dihalogenated diol intermediate, and aromatizing the obtained heteroaryl extended diol using a reducing agent under acidic conditions to obtain a terminally substituted heteroaryl acenodithiophene. SPECIFIC COMPOUNDS - 4 Compounds (I) are disclosed i.e. 2,8-bis(2-thienyl)-5,11-bis(triisopropylsilylethynyl)anthradithiophene of formula (Ia), 2,8-bis(2-thienyl)-5,11-bis(triethylsilylethynyl)anthradithiophene, 2,8-bis(5-fluoro-2-thienyl)-5,11-bis(triisopropylsilylethynyl)anthradithiophene and 2,8-bis(3,5-difluorophenyl)-5,11-bis(triisopropylsilylethynyl)anthradithiophene.    EXAMPLE - A solution of 2,8-iodo-5,11-dihydro-5,11 -bis(triisopropylsilylethynyl)-anthradithiophene-5,11-diol (1.41 g) and 2-(tributylstannyl)-thiophene (1.68 g) in anhydrous tetrahydrofuran (40 cm3) was degassed with bubbling nitrogen for 20 minutes. Bis(triphenylphosphine)palladium(II) chloride (105 mg) was added and the reaction mixture was stirred at 67 degrees C for 7 hours. The solution was concentrated in vacuum and the residue was purified to obtain fractions of 2,8-bis(thienyl)-5,11-dihydro-5,11-bis(triisopropylsilylethynyl)-anthradithiophene-5,11-diol as a pale-red solid and 2,8-bis(thienyl)-5,11-bis(triisopropylsilylethynyl)anthradithiophene as dark red solid. 2,8-Bis(2-thienyl)-5,11-dihydro-5,11-bis(triisopropylsilylethynyl)anthradithiophene-5,11-diol fraction was triturated with petroleum ether 40-60 and suction filtered to obtain 2,8-bis(2-thienyl)-5,11-dihydro-5,11-bis(triisopropylsilylethynyl)anthradithiophene-5,11-diol, as off-white solid (0.40 g). A solution of 2,8-bis(thienyl)-5,11-dihydro-5,11-bis(triisopropylsilylethynyl)anthradithiophene-5,11-diol (0.40 g) in tetrahydrofuran (10 ml) was added a solution of tin(II)chloride (0.208 g) in 1N hydrochloric acid (5 ml) and mixture was stirred at 20 degrees C for 30 minutes to obtain a purple-brown suspension. Methanol (approximately 30 ml) was added and the solid was collected by suction filtration then washed with methanol to obtain a dark-purple crystalline solid. The solid was recrystallized from toluene-ethanol to obtain 2,8-bis(2-thienyl)-5,11-bis(triisopropylsilylethynyl)anthradithiophene as a permanganate colored crystalline solid (0.301 g).