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ChemicalBook CAS DataBase List 1,6-Dibromopyrene
27973-29-1

1,6-Dibromopyrene synthesis

9synthesis methods
Specifically, pyrene (12.2g, 60 mmol) and 300 ml carbon tetrachloride are placed into a three-necked flask with a dropping funnel. Under room temperature, stirring, and nitrogen protection, bromine (11.5ml, 0.23mol) is dissolved in 50ml carbon tetrachloride, and then the solution is added to the reactor (the molar ratio of pyrene to bromine is 1:3.83). The mixed reaction solution is stirred at room temperature for 59 hours, then filtered, and the crude product is washed three times with 100ml methanol. The crude product is recrystallized with a mixed solvent of 260ml carbon tetrachloride and tetrahydrofuran to obtain 19.77g of pure 1,6-dibromopyrene, with a yield of 90.9% and a purity of 99.8%.
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Yield:27973-29-1 71.1% ，38303-35-4 20%

Reaction Conditions:

with bromine in chloroform; for 4 h;Inert atmosphere;Reflux;

Steps:

Intermediate 1: Synthesis of 1,6- and 1,8-dibromopyrene

58 g (0.287 mol) of pyrene are initially introduced in 1750 ml of chloroform. A solution of 31 ml (0.609 mol) of Br2 in 250 ml of chloroform is subsequently added dropwise at RT with exclusion of light. The reaction mixture is heated under reflux for 4 h. After cooling, the precipitated solid is filtered off with suction and washed with ethanol and dried. The solid obtained is recrystallised 3 times from CHCI3. Yield: 1 ,6- dibromopyrene 73.4 g (0.201 mol), 71.1% of theory, and 1 ,8-dibromopyrene 20.6 g (0.06 mol), 20% of theory.

References:

WO2013/185871,2013,A1 Location in patent:Page/Page column 24

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