1,4-DIBROMO-2,5-DIIODOBENZENE

to 250 ml reaction flask add 2.66g (11.7mmol) potassium periodate, lowering the temperature to 0 °C, adding 60 ml concentrated sulfuric acid. Stirring, add 5.82g (35.1mmol) potassium iodide, 15 minutes later, adding 5.52g (23.4mmol) to two bromobenzene and 24 ml concentrated sulfuric acid, 0 °C lower reaction 18 hours. Gradually increasing temperature to room temperature, the reaction 15 hours. The reaction solution is poured into the bottle in the ice, stirring, filtering the obtained filter cake is 1, 4 - dibromo - 2, 5 - diiodide of crude product, dissolving the filters cake Canada, dilute NaOH solution for washing, extraction, the organic phase dried, concentrated, recrystallized, shall 8.326g (yield 73percent) 1, 4 - dibromo - 2, 5 - diiodide, recrystallization using chloroform and tetrahydrofuran as the solvent of the mixed solution, the mixed solution in chloroform: tetrahydrofuran=2:1.Add 1, 4-dibromobenzene (10.00 g, 42.39 mmol) to a 500 ml one-neck flaskAnd iodine (43.04 g, 169.56 mmol), slowly add 200 ml of concentrated sulfuric acid at room temperature.A spherical condenser was placed above the single-mouth flask, and the flask was placed in an oil bath at 125 ° C to heat.The condensed water was turned on, refluxed, and reacted for 3 days.The color of the solution gradually changed from the initial purple to dark purple to black.The final product is white with black and the solution is black.Take a 1000ml large beaker, add a lot of ice, and pour the solution slowly after the reaction.Stir it to cool it, and filter it with a suction filter.Wash repeatedly with NaHCO3 and Na2S2O3 solution, In order to remove I2, the filter residue is filtered by suction filtration, and the filter residue is heated by DCM.The mixture was filtered and washed with water-free methanol to give a white solid. With DCM:PE=1:1 eluent, The silica gel powder was used as a carrier and purified by column chromatography.A white solid of 14.88 g was obtained in a yield of 72.0percent.S1 was synthesized using known methods. Its 20 g (85 mmol) of 1 , 4-dibromobenzene were dissolved in 250 mL of concentrated sulphuric acid at 80°C. Iodine (47.3 g, 187 mmol) was added to the reaction flask in several portions. After complete addition the reaction temperature was increased to 130°C and the mixture was heated during 2 days. The reaction mixture was cooled to room temperature and carefully poured into ice-water. The black solid was filtered-off and extensively washed with water, before it was dissolved in warm chlorobenzene (300 mL). The organic chlorobenzene layer was washed several times with a concentrated aqueous sodium thiosulfate solution and water. The organic layer was separated and dried over anhydrous magnesium sulphate. The solution was concentrated and then precipitated into well stirred methanol. The formed solid was filtered off and the title compound was recovered as a white solid (23.3 g, 48 mmol, 56percent yield). To a 1 L three-necked flask fitted with a mechanical stirrer were added 16.7 g (73.0 mmol) of periodic acid and 525 ml of sulfuric acid. After periodic acid was dissolved, 36.4 g (219 mmol) of potassium iodide was added portionwise. The content was cooled to a temperature of -30°C and 34.5 g (146 mmol) of 1, 4-dibromobenzene was added over a period of 5 minutes. The resulting mixture was stirred at -25°C for 36 hours. After the reaction mixture was poured into ice (2 kg), the whole was filtrated and a solid was taken out. The solid was dissolved in chloroform, the solution was washed with a 5percent aqueous sodium hydroxide solution and water, and the organic phase was dried over anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was recrystallized from chloroform to obtain white crystals (36.0 g, yield 50percent). Periodic acid 16.7g (73.0mmol) and 525ml sulfuric acid were added to a three-necked flask with a mechanical stirrer with 1l. After periodate was dissolved, it was added potassium iodide 36.4 g (219 mmol) portionwise. The temperature of the contents were cooled to -30 ° C., it was added over 1, 4-dibromobenzene 34.5g of (146mmol) 5 min. The resulting mixture was stirred for 36 hours at -25 ° C.. The reaction mixture was poured into ice (2Kg), filtered to remove solids. The solid was dissolved in chloroform, washed with 5percent aqueous solution of sodium hydroxide and water, the organic phase was dried with anhydrous magnesium sulfate. After concentration under reduced pressure, the residue was recrystallized from chloroform to give white crystals 36.0g (50percent yield). 1H NMR (CDCl3, 21 ): δ = 8.02 (s, 2H). Than that 1H NMR spectrum was consistent with the literature value, 1, 4-dibromo-2, 5-diiodobenzen it was confirmed that the obtained.

Molecular Weight:487.70
XLogP3:4.6
Exact Mass:487.65922
Monoisotopic Mass:485.66127
Heavy Atom Count:10
Complexity:106
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes