[Li+].C[Si]([N-][Si](C)(C)C)(C)C.[Br:11][C:12]1[CH:17]=[CH:16][N:15]=[C:14](F)[CH:13]=1.[CH:19]1([C:22]#[N:23])[CH2:21][CH2:20]1.C1(C)C=CC=CC=1>O>[Br:11][C:12]1[CH:17]=[CH:16][N:15]=[C:14]([C:19]2([C:22]#[N:23])[CH2:21][CH2:20]2)[CH:13]=1LiHMDS (1M in toluene, 17.6 mL, 17.6 mmol, 3.1 eq) is added dropwise to a cold (−5° C.) mixture of 4-bromo-2-fluoro-pyridine [Marsais, F. et al, Journal of Organic Chemistry, (1992), 57, 565-573] (1 g, 5.7 mmol), cyclopropanecarbonitrile (1.25 mL, 17 mmol, 3 eq), 4 Å molecular sieves and toluene (20 mL). The reaction mixture is allowed to warm to rt, stirred for 16 h, poured into H2O and filtered. The filtrate is diluted with EtOAc/H2O and extracted with EtOAc. The organic phase is washed with H2O and brine, dried (Na2SO4), filtered and concentrated. The residue is purified by silica gel column chromatography (Hex/EtOAc, 9:1), to afford 620 mg of the title compound as a white solid: ESI-MS: 223.1/225.1 [M+H]+; tR=4.22 min (System 1); TLC: Rf=0.25 (Hex/EtOAc, 9:1).
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