[Br:1][C:2]1[C:3]2[CH2:10][CH2:9][C:8](=[O:11])[C:4]=2[CH:5]=[N:6][CH:7]=1.[CH3:12][Mg]Br.[NH4+].[Cl-]>C1COCC1>[Br:1][C:2]1[C:3]2[CH2:10][CH2:9][C:8]([CH3:12])([OH:11])[C:4]=2[CH:5]=[N:6][CH:7]=1A brown suspension of 4-bromo-5H-cyclopenta[c]pyridin-7(6H)-one (intermediate A-4[B]) (424 mg, 2.0 mmol) in THF (5 mL) was cooled (−78° C.) and treated during 10 min with methylmagnesium bromide (2.1 mL, 3.0 mmol, 1.4 M in THF:toluene 1:3). The reaction was allowed to warm up to RT over 3 h then stirred for 1.5 h at RT. The mixture was poured on aq. sat. NH4Cl-solution and extracted with EtOAc (3×). The organic layer was dried over Na2SO4 and concentrated in vacuo. Purification by flash chromatography (50 g SiO2, Telos-cartridge, CH2Cl2/MeOH (4%)) gave the title compound (180 mg, 40%) as dark green viscous oil. MS: 228.0 (M+H+, 1Br).
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