[Mg:1].BrC(Br)C.[CH3:6][O:7][C:8]1[CH:13]=[CH:12][C:11](Br)=[C:10]([O:15][CH3:16])[C:9]=1[O:17][CH3:18].[Br-:19].C1COCC1>C1COCC1.[Li+].[Li+].[Cl-].[Cl-].[Cl-].[Cl-].[Cu+2]>[CH3:6][O:7][C:8]1[CH:13]=[C:12]([Mg:1][Br:19])[CH:11]=[C:10]([O:15][CH3:16])[C:9]=1[O:17][CH3:18]Magnesium (0.82 g, 33.74 mmol) was taken in flame dried 100 ml two necked flask and dry TEF (20 ml) was added. Then the dibromo ethane (0.1 ml) and trimethoxy bromobenzene (0.3 g, 1.20 mmol) were added at room temperature and stirred for 20 mins. The reaction initiates as indicated by temperature rise. The remaining bromide/THF (8.8 g, 35.48 mmol) in THF (20 ml) was added over 15 mints. After the addition was completed reaction mixture was stirred at 25° C. under nitrogen for 18 h. To the Grignard reagent at 0° C. was added a solution of dilithium tetrachlorocuprate (0.5 M, 0.76 ml, 0.38 mmol). The reaction was stirred at 0° C. for 15 mints and was used immediately for the coupling reaction.
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