[CH:1]([C:3]1[CH:4]=[CH:5][C:6]([C:9]#[N:10])=[N:7][CH:8]=1)=[O:2].C[Si](C)(C)[C:13]([F:16])([F:15])[F:14]>C1COCC1>[F:14][C:13]([F:16])([F:15])[CH:1]([C:3]1[CH:4]=[CH:5][C:6]([C:9]#[N:10])=[N:7][CH:8]=1)[OH:2]To a −78° C. solution of 5-formylpicolinonitrile (1.0 g, 7.58 mmol) and tetrabutylammonium triphenyldifluorosilicate (4.9 g, 9.10 mmol) in 60 mL of THF was added a solution of trimethyl(trifluoromethyl)silane (1.62 g, 114 mmol). The mixture was stirred for 20 min at −78° C. Then the cooling bath was changed to an ice bath. After stirring for another 30 min, the reaction was quenched with sat. NH4Cl(aq.). The mixture was extracted with EtOAc (3×). The organic layer was washed with sat. NaHCO3 (aq.), brine, then dried (MgSO4) and concentrated. The product 5-(2,2,2-trifluoro-1-hydroxyethyl)picolinonitrile (600 mg) was obtained by silica gel chromatography (elution with 0-40% EtOAc/Hex).
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