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ChemicalBook CAS DataBase List 2,2'-Dibromobiphenyl
13029-09-9

2,2'-Dibromobiphenyl synthesis

11synthesis methods
Pd(PPh3)4 (18.5 mg, 0.016 mmol, 4 mol) and indium (45.9 mg, 0.4 mmol, 1 equivalent) were added to a solution of 2-bromoiodobenzene (0.4 mmol) in DMF (2 ml). The resulting mixture was heated at 100°C at room temperature. The reaction process was monitored by thin-layer chromatography, with ethyl acetate and n-hexane (1:4 or 1:10, depending on the polarity of the substrate) as the developing solvent. After 34 hours of reaction, the raw materials reacted completely, and a saturated sodium bicarbonate solution (4 ml) was added to quench the reaction, and the reaction solution was extracted with ethyl acetate (10 ml). The ethyl acetate layer was washed twice with water (4 ml) and then once with brine (4 ml). The organic phase was dried over MgSO4, filtered and concentrated under reduced pressure. The concentrate was chromatographed on silica gel using n-hexane or a solution of ethyl acetate and n-hexane for purification and separation to obtain the target product 2,2'-Dibromobiphenyl.
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Yield:13029-09-9 84%

Reaction Conditions:

Stage #1:2,3-dibromobenzene with n-butyllithium in tetrahydrofuran;hexane at -78; for 0.5 h;Inert atmosphere;
Stage #2: with hydrogenchloride in tetrahydrofuran;hexane;water at 0;Inert atmosphere;

Steps:

2,2'-Dibromobiphenyl (1a)
6.25 mL n-BuLi (10 mmol, 1.6 M in n-hexane) was added dropwise to a solution of4.72 g (20 mmol) of o-dibromobenzene in THF (50 mL) at -78 °C and stirred for 30min. After addition, the mixture was warmed to 0 °C and subsequently hydrolyzedwith aqueous HCl (10 mL, 3 N). The organic solvents were removed by rotaryevaporation, and the residue was extracted with diethyl ether. The combined filtrateswere concentrated under reduced pressure and the crude product was purified byrecrystallization in hexane to give 2.59 g pure 2,2'-dibromobiphenyl in 84% yield. 1HNMR (400 MHz, CDCl3) δ 7.66-7.68 (m, 2H), 7.38-7.40 (m, 2H), 7.23-7.29 (m, 4H).

References:

Ma, Jun;Li, Gaoqiang;Qiao, Yan;Tu, Jingxuan;Liu, Sha;Xu, Feng [Synlett,2015,vol. 26,# 14,art. no. ST-2015-W0198-L,p. 1991 - 1996] Location in patent:supporting information

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