3-Bromo-5-nitroaniline

3-Bromo-5-nitroanilineTo a solution of 1-bromo-3, 5-dinitrobenzene (3.0 g, 12 mmol, 1 equiv) in EtOH (15 mL) at room temperature was added 20percent of (NHb) 3-Bromo-5-nitroanilineTo a solution of l-bromo-3, 5-dinitrobenzene (20 g, 80.97 mmol) in acetic acid (120 ml) at 90 °C was added iron powder (1 1.3 g, 202.4 mmol, 2.5 eq) slowly portion- wise over a period of 30 min (caution: highly exothermic reaction). After completion of the addition, the mixture was quenched by the addition of crushed ice. The precipitate formed was filtered and was washed with cold water to obtain orange solid. The solid was dried under vacuum to give the product in 80 percent yield (14 g). 1H NMR (300 MHz, CDC1To a solution of 1-bromo-3, 5-dinitrobenzene (20 g, 80.97 mmol) in acetic acid (120 ml) at 90° C. was added iron powder (11.3 g, 202.4 mmol, 2.5 eq) slowly portion-wise over a period of 30 min (caution: highly exothermic reaction). The 2.47g3, 5-dinitrobromobenzen (10mmol), 3.68g ammonium chloride (68mmol), 0.59 ml concentrated ammonia dissolved in 17 ml water, in the 80 °C added in batches after dissolving solid all 8.38g nine hydrated sodium sulfide (35mmol), to be all maintained after adding 80 °C reaction 20 min, then is filtered, filtrate cooling by ethyl acetate extraction, the organic phase is dried with anhydrous magnesium sulfate, filter, evaporate the solvent crude, column separation (petroleum ether: ethyl acetate = 100 : 1, 10:1) to obtain light yellow solid 3-nitro-5-bromoaniline1.53g, yield: 70.5percentc) N-(3-Bromo-5-nitrophenyl)acetamideAcetic anhydride (14 ml) was added dropwise at 0 C to c) Acetic anhydride (14 ml) was added dropwise at 0 C. to Dissolve General procedure: 2-Nitro-aniline (1 eq) was dissolved in concentrated hydrochloric acid (20 eq).Then, it was cooled to -10 C, and an aqueous solution of sodium nitrite (1.05 eq) wasadded dropwise and stirred for 2 h. Then the reaction solution was cooled to -30 Cand transferred into a solution of SnCl2 (3 eq) in concentrated hydrochloric acid, which was pre-cooled to -30 C. Then the reaction solution was warmed to -20 Cand stirred for another 1 h. The precipitate was filtered and dried to give the targetcompound.For 100 ml is added to the flask 2.17gExample 1323-Bromo-5-nitroanilineTo a solution of 1-bromo-3, 5-dinitrobenzene (3.0 g, 12 mmol, 1 equiv) in EtOH (15 mL) at room temperature was added 20% of (NH4)2S in water (9.0 mL, 26 mmol, 2.2 equiv). The mixture was then refluxed for 2 hours. After being cooled to room temperature, the reaction mixture was diluted with EtOAc and water. The organic layer was separated, washed with brine and concentrated. The residue was purified by column chromatography on silica gel using EtOAc/hexanes (1:4) as eluent to give 2.2 g of b) 3-Bromo-5-nitroanilineTo a solution of l-bromo-3, 5-dinitrobenzene (20 g, 80.97 mmol) in acetic acid (120 ml) at 90 C was added iron powder (1 1.3 g, 202.4 mmol, 2.5 eq) slowly portion- wise over a period of 30 min (caution: highly exothermic reaction). After completion of the addition, the mixture was quenched by the addition of crushed ice. The precipitate formed was filtered and was washed with cold water to obtain orange solid. The solid was dried under vacuum to give the product in 80 % yield (14 g). 1H NMR (300 MHz, CDC13): delta 10.55 (br s, 2H), 8.46 (s, 1H), 8.19 (s, 1H), 8.02 (s, 1H).To a solution of 1-bromo-3, 5-dinitrobenzene (20 g, 80.97 mmol) in acetic acid (120 ml) at 90 C. was added iron powder (11.3 g, 202.4 mmol, 2.5 eq) slowly portion-wise over a period of 30 min (caution: highly exothermic reaction). After completion of the addition, the mixture was quenched by the addition of crushed ice. The precipitate formed was filtered and was washed with cold water to obtain orange solid. The solid was dried under vacuum to give the product in 80% yield (14 g). 1H NMR (300 MHz, CDCl3): delta 10.55 (br s, 2H), 8.46 (s, 1H), 8.19 (s, 1H), 8.02 (s, 1H).The 2.47g3, 5-dinitrobromobenzen (10mmol), 3.68g ammonium chloride (68mmol), 0.59 ml concentrated ammonia dissolved in 17 ml water, in the 80 C added in batches after dissolving solid all 8.38g nine hydrated sodium sulfide (35mmol), to be all maintained after adding 80 C reaction 20 min, then is filtered, filtrate cooling by ethyl acetate extraction, the organic phase is dried with anhydrous magnesium sulfate, filter, evaporate the solvent crude, column separation (petroleum ether: ethyl acetate = 100 : 1, 10:1) to obtain light yellow solid l-Bromo-3, 5-dinitrobenzene (14.77 g, 59.8 mmol) was dissolved in methanol (150 mL) and toluene (374 mL) and a solution of sodium hydrosulfide (10.06 g, 179 mmol) in water (10 mL) and methanol (150 mL) was added dropwise over a period of 60 minutes. The reaction was stirred at 80 C for 3 hours. The reaction mixture was cooled to room temperature and then extracted 3 times with ethyl acetate. The organic layers were combined, washed with brine, dried with MgS04, filtered, and concentrated under reduced pressure. The crude material required no further purification to yield 12.93 g (59.6 mmol, 100%) of 1-Bromo-3, 5-dinitrobenzene (4.91g, 19.9mmol) was dissolved in ethanol (20mL), 20% -24% (NH4) 2S aqueous solution (14.9mL, 43.7mmol) was added, and the temperature was raised to 90 C. Reaction 0.5h. Cool to room temperature, filter to remove insoluble impurities with diatomaceous earth, add ethyl acetate (50mL × 3), wash with water (40mL), dry with anhydrous magnesium sulfate, spin dry the organic phase, filter and dry with a small amount of ether to obtain 3.678g, the column layer of the filtrate Analysis (P / E = 5: 1) gave 562 mg of an orange solid with a total yield of 98.28% and melting point: 125-127 C.