[F:1][C:2]([F:11])([F:10])[C:3]1[CH:8]=[CH:7][C:6](Br)=[CH:5][N:4]=1.[Li]C(CC)C.CNN(NC)[C:20](=[O:22])[CH3:21].O>CCOCC>[F:1][C:2]([F:11])([F:10])[C:3]1[N:4]=[CH:5][C:6]([C:20](=[O:22])[CH3:21])=[CH:7][CH:8]=1
To a solution of 2-trifluoromethyl-5-bromopyridine (5.0 g, 22 mmol) in Et2O (50 mL) was added sec-BuLi (0.91 M in cyclohexane, 24 mL, 22 mmol) at −78° C. After 10 minutes of stirring, N,N-dimethylaminoacetamide (2.3 mL, 24 mmol) dissolved in Et2O (10 mL) was added drop wise. Stirring was continued at −78° C. for 1 h and then at rt over night. The reaction mixture was poured into water (100 mL) and the water phase was extracted with Et2O (3×100 mL). Combined organics were washed with water and brine and dried (MgSO4). After careful evaporation of the solvent, the crude was purified by column chromotography (SiO2, pentane/ether 9/1) to give the title compound (2.3 g, 12 mmol, 54%) as a light yellow solid.
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