TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The bromination reaction is performed by reacting 5-alkylthiophene-(3,4-c)-pyrrolo-4,6-diketone with brominating agent at mol ratio of 1.0:2.0-1.0:4.0 in the presence of an organic solvent at 10-30 degrees C for 12-48 hours to obtain the dibromine product. The suzuki reaction is performed by reacting the (II) with the dibromine product at the mol ratio of 1.0:0.95-1.05 in an anaerobic environment in the presence of catalyst, alkali solution and organic solution at 65-120 degrees C for 24-72 hours to obtain (I). The (II) is prepared by mixing the 2,7-dibromo-9,9-dialkyl silicon fluorene with lithium alkyl at mol ratio of 1.0:2.0-1.0:4.0 in an organic solvent at (-100)-(-25) degrees C, where the mixture is added with 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-bioxapentaborane for 24-48 hours to obtain (II). The 5-alkylthiophene-(3,4-c)-pyrrolo-4,6-diketone is prepared by mixing thiophene-3,4-dicarboxylic acid with acetic anhydride reacting for 12-24 hours in the presence of an organic solvent. The obtained product is dried and added with alkylamine, which is heated at 100-120 degrees C for 24-32 hours and cooled. The obtained product is refluxed with thionyl chloride at 80-100 degrees C for 1-12 hours to obtain the product, which is further separated and purified. Preferred Composition: The dose of alkali solution is 2-20 times of the mol dosage of compound (II). The dose of the 2-isopropoxy-4,4,5,5tetramethyl-1,3,2-bioxapentaborane is 2.0-4.0 times of the dose of the 2,7dibromo-9,9-dialkyl silicon fluorene. Preferred Components: The organic solvent is the mixed solvent of sulfuric acid and trifluoroacetic acid, N,N-dimethylformamide, tetrahydrofuran, diethyl ether, dichloromethane, trichloromethane, ethyl acetate and acetic acid. The alkali solution is an aqueous solution of alkali metal hydroxide or alkali metal carbonate or the aqueous solution of tetralkyl ammonium hydroxide. The organic solvent is methylbenzene, tetrahydrofuran, trichloromethane or ethyl acetate. The organic solvent is tetrahydrofuran, diethyl ether, dichloromethane or ethyl acetate. Preferred Definitions:    R1-R3=8-20Calkyl;and    n=20-80