TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (claimed): 1-(2-Amino-phenyl)-1,3-dihydro-benzoimidazol-2-one is heated in phosphoric acid, polyphosphoric acid, methanesulfonic acid/phosphorus pentoxide, methanesulfonic acid, or sulfuric acid to obtain 9H-4b,9,10-triaza-indeno(1,2-a)indene. The obtained compound is then reacted to obtain compound (I) in which X6 is N, X7 is N-R1, and R9+R10 is substituted benzene ring. Preferred Definitions:    R9+R10=benzene ring;    X6=N;    R2-R5=H;    A1-A4=group of formula (iii), (iv), (v) or (vi);and    R6=group of formula (vii), (viii) or -Si(Ph)3.    SPECIFIC COMPOUNDS - 25 Compounds (I) are specifically claimed e.g. 9-(8'-carbazol-9-yl-(2,2')bi(dibenzofuranyl)-8-yl)-9H-4b,9,10-triaza-indeno(1,2-a)indene of formula (IA), 10-(3-(1,8,10-triazatetracyclo(7.7.0.02,7.011,16)hexadeca-2(7),3,5,9,11(16),12,14-heptaen-8-yl)phenyl)-1,8,10-triazatetracyclo(7.7.0.02,7.011,16)hexadeca-2(7),3,5,8,11(16),12,14-heptaene, 10-(3-(3-(1,8,10-triazatetracyclo(7.7.0.02,7.011,16)hexadeca-2(7),3,5,9,11(16),12,14-heptaen-8-yl)phenyl)phenyl)-1,8,10-triazatetracyclo(7.7.0.02,7.011,16)hexadeca-2(7),3,5,8,11(16),12,14-heptaene, 10-(11-(1,8,10-triazatetracyclo(7.7.0.02,7.011,16)hexadeca-2(7),3,5,9,11(16),12,14-heptaen-8-yl)-8-oxatricyclo(7.4.0.02,7)trideca-1(13),2(7),3,5,9,11-hexaen-4-yl)-1,8,10-triazatetracyclo(7.7.0.02,7.011,16)hexadeca-2(7),3,5,8,11(16),12,14-heptaene, and 9-(3,5-bis-dibenzofuran-2-yl-phenyl)-9H-4b,9,10-triaza-indeno(1,2-a)indene.    EXAMPLE - (In g) 3-(2-aminophenyl)-1H-benzimidazol-2-one (11.3) was added to polyphosphoric acid (50) at 180 degrees C. The reaction mixture was stirred at 220 degrees C for 3 hours under nitrogen and poured into water. The product was filtered off and washed with water and methanol. 30% Sodium hydroxide aqueous solution (50 ml) was added to a suspension of the product in tetrahydrofuran (200 ml). The mixture was stirred for 30 minutes, the organic phase was separated and dried, and solvent was distilled off to obtain 9H-4b,9,10-triaza-indeno(1,2-a)indene (9.26) with a yield of 89%. 2-Bromo-8-iodo-dibenzofuran (5), cesium carbonate (8.74), copper(I) iodide (255 mg), and L-proline (309 mg) were added to the obtained compound (2.78) in dimethylformamide (75 ml) under nitrogen. The reaction mixture was heated for 19 hours at 150 degrees C and filtered. The organic phase was washed with water, the solvent was distilled off, and the residue was purified using toluene/ethyl acetate to obtain 9-(8-bromo-dibenzofuran-2-yl)-9H-4b,9,10-triaza-indeno(1,2-a)indene (2.29) with a yield of 37.7%. 9-(8-(4,4,5,5-Tetramethyl-(1,3,2)dioxaborolan-2-yl)-dibenzofuran-2-yl)-9H-carbazole (1.98) and potassium phosphate tribasic monohydrate (4.02), dioxane (15 ml), toluene (60 ml), and water (12 ml) were added to the obtained compound (1.5). The mixture was degassed with argon. 2-Dicyclohexylphosphino-2',6'-dimethoxybiphenyl (81 mg) and palladium(II) acetate (74 mg) were added, and the reaction mixture was degassed with argon and stirred for 4.5 hours at 100 degrees C under argon. 1% Sodium cyanide solution (40 ml) was added and the reaction mixture was refluxed for 1 hour. Dichloromethane was added, the organic phase was washed with water and dried, and the residue was purified using toluene and toluene/ethyl acetate to obtain 9-(8'-carbazol-9-yl-(2,2')bi(dibenzofuranyl)-8-yl)-9H-4b,9,10-triaza-indeno(1,2-a)indene (1.42) with a yield of 61%. The obtained compound provided organic light-emitting device having a lifetime of 125 hours at 4000 nits and CIE values of 0.17/0.33.