TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation: No preparation method is given. Preferred Definitions:    R1-R4 = phenyl, furyl, thienyl, pyridyl, pyrimidyl, benzothiazolyl or benzoimidazolyl.    SPECIFIC COMPOUNDS - 4 Compounds (A) are specifically claimed i.e. 5,8-bis-(2,4-difluoro-phenyl)-2,3-diphenyl-quinoxaline of formula (Ia), 5,8-bis-(2,4-difluoro-phenyl)-2,3-di-pyridin-2-yl-quinoxaline, 5,8-bis-(9,9-di-p-tolyl-9H-fluoren-2-yl)-2,3-diphenyl-quinoxaline and 5,8-bis-(9,9-di-p-tolyl-9H-fluoren-2-yl)-2,3-di-pyridin-2-yl-quinoxaline.    EXAMPLE - Benzothiadiazole (13.6 g) and hydrogen bromide aqueous solution (300 ml) were added to round-bottom flask (1000 ml) and heated to reflux. Bromine (15.4 ml) was then slowly dropped to the above solution and reacted overnight. Sodium thiosulfate aqueous solution was added to quench the reaction, and the resulting solution was filtered. The filtered solid was then washed with acetone to give 4,7-dibromo-benzo(1,2,5)thiadiazole (Z2). (Z2) (2.94 g), ethanol (150 ml) and tetrahydrofuran (50 ml) were added to a round-bottom flask (250 ml) and stirred for 10 minutes. Sodium borohydride (1.51 g) was then added and heated to reflux. The resulting solution was filtered and extracted using ether and saturated saline to obtain organic layer. The organic layer was then collected and concentrated to give 3,6-dibromo-benzene-1,2-diamine (Z3). (Z3) (585 mg), 1,2-diphenyl-ethane-1,2-dione (420 mg), p-toluenesulfonic acid monohydrate (specific quantity) and trichloromethane (20 ml) were added to a two-necked flask (50 ml) and heated to reflux for 12 hours. Sodium bicarbonate aqueous solution (20 ml) was added to quench the reaction. The resulting solution was then extracted using dichloromethane (20 ml). The organic layer was then washed with saturated saline and then collected. Water was removed from the collected solution, filtered and concentrated to give 5,8-dibromo-2,3-diphenyl-quinoxaline (Z5). 2,4-Difluorophenylboronic acid (695 mg), (Z5) (910 mg), tetrakis(triphenylphosphine)palladium(0) (115.5 mg), potassium carbonate (2.1 ml), and dimethoxyethane (50 ml) were added to two-necked flask (150 ml) and heated to reflux for 24 hours. The resulting solution was then extracted using ethyl acetate (20 ml) for several times. The organic layer was then washed with saturated saline and collected. The collected solution was filtered and concentrated to give 5,8-bis-(2,4-difluoro-phenyl)-2,3-diphenyl-quinoxaline (yield 72%).