[Mg].[CH:2]1(Br)[CH2:4][CH2:3]1.[CH3:6][N:7]1[CH:11]=[CH:10][CH:9]=[C:8]1[C:12]([C:14]1[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=1)=[O:13].[Cl-].[NH4+]>O1CCCC1.O>[CH:2]1([C:12]([C:8]2[N:7]([CH3:6])[CH:11]=[CH:10][CH:9]=2)([C:14]2[CH:19]=[CH:18][CH:17]=[CH:16][CH:15]=2)[OH:13])[CH2:4][CH2:3]1
To a suspension of magnesium turnings (5.29 g, 0.22 mole) in anhydrous tetrahydrofuran (70 ml), cyclopropyl bromide (26.35 g, 0.22 mole) in tetrahydrofuran (50 ml) was added dropwise under nitrogen. The reaction mixture was heated at reflux for one h after the initial exotherm had subsided before (N-methylpyrrol-2-yl)phenylketone (13.3 g, 0.072 mole) (J. White and G. McGillivray, J. Org. Chem., (1977), 42, 4248, R. Greenhouse and C. Ramirez, J. Org. Chem., (1985), 50, 2961) in anhydrous tetrahydrofuran (50 ml ) was introduced dropwise. After heating the reaction mixture at reflux for 3 h it was cooled and saturated, aqueous ammonium chloride solution (95 ml) and water (150 ml) were added. The mixture was extracted with ethyl acetate (3×200 ml) and the combined extracts were dried (MgSO4). Flash chromatography of the residue on evaporation on silica gel eluting with heptane/tetrahydrofuran (9:1) provided the title compound as an oil (9.9 g, 46%) which solidified on standing. T.l.c. rf=0.35 (SiO2, heptane/THF (7:3)).
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