2-(2-amino-4-bromophenyl)-5-bromoaniline

Conditions: temp:190.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,4′-dibromo-2,2′-diaminobiphenyl (3.5 g, 10.23 mmol) was dissolved in phosphoric acid and heated at 190° C. for 24 hours. The reaction mixture was cooled to room temperature and then NaHCO3 (aq) was gradually added thereto to form a solid. Then, the solid was filtered to obtain 2,7-dibromocarbazole (2.2 g, 66%), the compound represented by formula e. MS [M+] 323. The reaction mixture was cooled to room temperature to form a solid Then, the solid was filtered

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,4′-dibromo-2,2′-dinitrobiphenyl (6.1 g, 15.17 mmol) was stirred in HCl 30 ml/EtOH 75 ml, Sn powder (7.2 g, 60.68 mmol) was added thereto, and then the reaction mixture was refluxed for 24 hours. Next, the reaction mixture was cooled to room temperature, neutralized with 10% NaOH solution, and then recrystallized in ethanol to obtain 4,4′-dibromo-2,2′-diaminobiphenyl (3.5 g, 67%). MS [M+H] 341. was added the reaction mixture was refluxed for 24 hours recrystallized in ethanol

Conditions: temp:190.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,4′-dibromo-2,2′-diaminobiphenyl (3.5 g, 10.23 mmol) was dissolved in phosphoric acid and heated at 190° C. for 24 hours. The reaction mixture was cooled to room temperature and then NaHCO3 (aq) was gradually added thereto to form a solid. Then, the solid was filtered to obtain 2,7-dibromocarbazole (2.2 g, 66%), the compound represented by formula e. MS [M+] 323. The reaction mixture was cooled to room temperature to form a solid Then, the solid was filtered

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,4′-dibromo-2,2′-dinitrobiphenyl (6.1 g, 15.17 mmol) was stirred in HCl 30 ml/EtOH 75 ml, Sn powder (7.2 g, 60.68 mmol) was added thereto, and then the reaction mixture was refluxed for 24 hours. Next, the reaction mixture was cooled to room temperature, neutralized with 10% NaOH solution, and then recrystallized in ethanol to obtain 4,4′-dibromo-2,2′-diaminobiphenyl (3.5 g, 67%). MS [M+H] 341. was added the reaction mixture was refluxed for 24 hours recrystallized in ethanol

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 15 (11.0 g, 27.4 mmol) in 135 mL of absolute ethanol was added 32% w/w aqueous HCl (78.0 mL). Tin powder (13.0 g, 108.5 mmol) was then added in portions over 10 min, and the reaction mixture was heated to reflux at 100° C. for 2 h. After cooling, the mixture was poured into ice water (400 mL) and then made alkaline with 20% w/w aqueous NaOH solution until the pH was 9.0. The product was next extracted with diethyl ether and the organic layer was washed with brine, dried over anhydrous Na2SO4, filtered, and then evaporated to dryness to give pure product as light-brown crystals that could be used without further purification (8.6 g, 92%). 1H NMR (CDCl3): δ 6.92 (6H, s), 3.78 (4H, br s, NH2) ppm; 13C NMR (CDCl3): δ 118.2, 121.9, 122.1, 122.8, 132.4, 145.3 ppm; m.p. 118-119° C. the reaction mixture was heated After cooling The product was next extracted with diethyl ether the organic layer was washed with brine dried over anhydrous Na2SO4 filtered evaporated to dryness to give pure product as light-brown crystals that could be used without further purification (8.6 g, 92%)

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 4,4′-Dibromo-2,2′-dinitro-biphenyl (15.0 g, 37.3 mmol) in ethanol (abs., 186 cm3) was added 32% w/w aqueous HCl (124 cm3). Tin powder (17.6 g, 147 mmol) was added portion-wise over 10 minutes and the reaction mixture was heated to reflux at 100° C. for 2 hours. After cooling, the mixture was poured into ice water (ca. 400 cm3) and then basified with 20% w/w aqueous NaOH solution (150 cm3). The product was extracted with diethyl ether and the organic layer washed with brine, dried over anhydrous MgSO4 and evaporated to dryness. Purification by recrystallization from ethanol afforded the title compound (9.2 g, 72%) as light brown crystals (Found: C, 42.1; H, 3.0; N, 8.0. C12H10Br2N2 requires C, 42.2; H, 3.0; N 8.2%); νmax/cm−1 (Neat solid) 792, 994, 1406, 1477, 1608, 3210, 3357, 3443; δH(400 MHz, CDCl3) 6.92 (6H, s, ArH), 3.78 (4H, brs, NH2); δC(100 MHz, CDCl3) 118.1, 121.7, 122.0, 122.7, 132.2, 145.4; m/z (ES) 340.9283 ([M+H)+. C12H11Br2N2 requires 340.9284), 343.1 (100%), 263.1 (80), 185.1 (25). the reaction mixture was heated After cooling The product was extracted with diethyl ether the organic layer washed with brine dried over anhydrous MgSO4 evaporated to dryness Purification by recrystallization from ethanol

Conditions: temp:100.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: To a solution of 15 (11.0 g, 27.4 mmol) in 135 mL of absolute ethanol was added 32% w/w aqueous HCl (78.0 mL). Tin powder (13.0 g, 108.5 mmol) was then added in portions over 10 min, and the reaction mixture was heated to reflux at 100° C. for 2 h. After cooling, the mixture was poured into ice water (400 mL) and then made alkaline with 20% w/w aqueous NaOH solution until the pH was 9.0. The product was next extracted with diethyl ether and the organic layer was washed with brine, dried over anhydrous Na2SO4, filtered, and then evaporated to dryness to give pure product as light-brown crystals that could be used without further purification (8.6 g, 92%). 1H NMR (CDCl3): δ 6.92 (6H, s), 3.78 (4H, br s, NH2) ppm; 13C NMR (CDCl3): δ 118.2, 121.9, 122.1, 122.8, 132.4, 145.3 ppm; m.p. 118-119° C. the reaction mixture was heated After cooling The product was next extracted with diethyl ether the organic layer was washed with brine dried over anhydrous Na2SO4 filtered evaporated to dryness to give pure product as light-brown crystals that could be used without further purification (8.6 g, 92%)

Conditions: temp:190.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,4′-dibromo-2,2′-diaminobiphenyl (3.5 g, 10.23 mmol) was dissolved in phosphoric acid and heated at 190° C. for 24 hours. The reaction mixture was cooled to room temperature and then NaHCO3 (aq) was gradually added thereto to form a solid. Then, the solid was filtered to obtain 2,7-dibromocarbazole (2.2 g, 66%), the compound represented by formula e. MS [M+] 323. The reaction mixture was cooled to room temperature to form a solid Then, the solid was filtered

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 4,4′-dibromo-2,2′-dinitrobiphenyl (6.1 g, 15.17 mmol) was stirred in HCl 30 ml/EtOH 75 ml, Sn powder (7.2 g, 60.68 mmol) was added thereto, and then the reaction mixture was refluxed for 24 hours. Next, the reaction mixture was cooled to room temperature, neutralized with 10% NaOH solution, and then recrystallized in ethanol to obtain 4,4′-dibromo-2,2′-diaminobiphenyl (3.5 g, 67%). MS [M+H] 341. was added the reaction mixture was refluxed for 24 hours recrystallized in ethanol