[CH2:1]([C:5]1[CH:6]=[C:7]([CH:14]=[C:15]([CH3:17])[N:16]=1)[C:8](N(OC)C)=[O:9])[CH:2]([CH3:4])[CH3:3].[CH2:18]1COCC1>C[Mg]Br.CCOCC>[CH2:1]([C:5]1[CH:6]=[C:7]([C:8](=[O:9])[CH3:18])[CH:14]=[C:15]([CH3:17])[N:16]=1)[CH:2]([CH3:4])[CH3:3]To a solution of 2-isobutyl-N-methoxy-6,N-dimethyl-isonicotinamide (410 mg, 1.74 mmol) in THF (10 mL), methyl magnesium bromide (1.17 mL of a 3 M solution in ether, 3.47 mmol) is added at 5° C. The mixture is stirred at 5° C. for 1.5 h. The reaction is quenched by adding NH4Cl. The mixture is diluted with EA (50 mL), washed with sat. aq. NaHCO3, dried over Na2SO4, filtered and concentrated. The crude product is purified by CC on silica gel eluting with heptane:EA 4:1 to give 1-(2-isobutyl-6-methyl-pyridin-4-yl)-ethanone (280 mg) as a colourless oil. LC-MS: tR=0.84 min; 1H NMR (CDCl3): δ 0.96 (d, J=6.5 Hz, 6H), 2.08-2.20 (m, 1H), 2.62 (s, 3H), 2.65 (s, 3H), 2.74 (d, J=7.3 Hz, 2H), 7.37 (s, 1H), 7.42 (s, 1H).
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