To a sealed tube were added 5-bromo-2-chloro-3-fluoropyridine 190-1 (210 mg, 1.0 mmol), 0.5 M (2-tert-butoxy-2-oxoethyl) zinc(II) chloride 86-5 in ether (2.4 mL, 1.2 mmol), Pd(dba)2 (29 mg, 0.005 mmol), Q-phos (71 mg, 0.10 mmol) and THF (3 mL). The reaction mixture was bubbled with nitrogen for 1 minute and stirred at 100° C. for 1 hour. After cooling to room temperature, all the solvents were evaporated and the residue was redissolved in ethyl acetate, washed with water and brine, dried over Na2SO4 and concentrated to dryness by rotary evaporation. The crude product was purified by silica gel flash chromatography and eluted with 20% ethyl acetate in hexane to give tert-butyl 2-(6-chloro-5-fluoropyridin-3-yl)acetate 190-3. MS m/z 246.1 (M+1).
