2,5-Dibromo-p-xylene

white to slightly yellow shiny crystalline powder

The cylinder was weighed in dichloromethane (50 mL) and placed in a 150 mL two-neck round bottom flask.Use a pipette to accurately measure the amount of p-xylene (16.96 g, 0.16 mol, 19.8 mL) in dichloromethane.Weigh elemental iodine (0.1g, 0.8mmol) into the mixture, Install an air condensing tube at one of the openings of the flask and connect the tail gas recovery device.The other opening of the flask is fitted with a constant pressure feeder.And use a pipette to accurately take liquid bromine (18mL) and transfer it to a constant pressure feeder.And add a layer of water (about 0.3-0.5cm) on top of the liquid bromine to prevent the liquid bromine from evaporating.A stopper is then placed on the top of the constant pressure feeder.The temperature of the reaction system was controlled at 12°C under strong stirring and dark conditions.Add liquid bromine dropwise to the mixture (40 to 50 minutes).Take care not to drip the upper aqueous layer into the reaction solution. Reaction 18h. After the reaction is completed, 40 mL w(KOH)=25percent aqueous solution was added and stirred vigorously for another 30 min.The reaction mixture was transferred to a separatory funnel.The lower organic phase was separated and washed with water (2 x 50 mL), dried over anhydrous CaCl2, filtered, Solvent removal under reduced pressure, The residue was recrystallized from ethanol (2 x 300 mL) to give white needles.Yield 96.5percent (40.44 g), General procedure: 1-Methoxy-3, 5-dimethylbenzene(100mg, 0.73 mmol), N-Bromosuccinimide (NBS, 260 mg, 1.46 mmol) and one ball (5 mmdiameter, stainless steel) were transferred to a milling jar (10 mL, stainlesssteel). The ball-milling operation was performed and the progress of reaction was monitored by TLC/General procedure: 1-Methoxy-3, 5-dimethylbenzene (100mg, 0.73 mmol), N-Bromosuccinimide (NBS, 260 mg, 1.46 mmol) and one ball (5 mmdiameter, stainless steel) were transferred to a milling jar (10 mL, stainlesssteel). The ball-milling operation was performed and the progress of reactionwas monitored by TLC/Iodine (78 mg, 0.33 mmol) was added to p-xylene (6.13 mL, 50.0 mmol), the mixture was cooled to 0 °C, and bromine (5.20 mL, 101 mmol) was added dropwise over 10 min. The ice bath was removed and the reaction stirred at rt for 16 h in the absence of light. The reaction was quenched with 20percent aq. KOH and stirred for 15 min while the solution became colorless. The solid precipitate was filtered and rinsed 2 x with 100 mL of H

Molecular Weight:263.96
XLogP3:4
Exact Mass:263.89723
Monoisotopic Mass:261.89928
Heavy Atom Count:10
Complexity:99.8
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes