[Li+].[Cl-].Br[C:4]1[CH:9]=[CH:8][CH:7]=[CH:6][C:5]=1[Br:10].C([Cu])#N.[C:14](Cl)(=[O:21])[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>C1COCC1>[Br:10][C:5]1[CH:6]=[CH:7][CH:8]=[CH:9][C:4]=1[C:14]([C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)=[O:21]A dry and argon flushed 10 mL flask, equipped with a magnetic stirrer and a septum, was charged with i-PrMgCl.LiCl (1 mL, 1.05 M in THF, 1.05 mmole), the reaction mixture was cooled to −15° C. and 1,2-dibromobenzene (235.9 mg, 1 mmole) was then added dropwise. The Br/Mg-exchange was complete after 1.5 h (checked by GC analysis of reaction aliquots, conversion more than 98%) and solution of CuCN.2LiCl (0.1 mL, 1.0 M in THF, 0.1 mmole) was added. After stirring for 10 min at −15° C. benzoyl chloride (140.6 mg, 1 mmole) was added. The reaction mixture was stirred for 1 h at −15° C. and was then quenched with sat. NH4Cl solution (2 mL) and also 5 drops of concentrated NH3 was added. The aqueous phase was extracted with ether (3×4 mL) and the organic fractions were washed with brine (5 mL), dried (Na2SO4) and concentrated in vacuo. The crude residue was purified by flash chromatography (dichloromethane) yielding the ketone (2ka) as a white cristals (219.3 mg, 84%). 1H-NMR (CDCl3, 200 MHz): δ=7.86-7.78 (m, 2H); 7.68-7.56 (m, 2H); 7.52-7.30 (m, 5H).
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