A mixture of (5R)-(−)-3-[3-fluoro-4-iodophenyl]-2-oxo-5-oxazolidinecarboxamide (Step 3, 422 mg, 1.21 mmol), 3-(trimethylstannyl)pyridine (Step 4, 350 mg, 1.45 mmol), tris(dibenzylideneacetone)dipalladium(0) (22 mg, 0.0242 mmol), triphenylarsine (59 mg, 0.194 mmol) and copper(I) iodide (9 mg, 0.0484 mmol) in N-methyl-2-pyrrolidinone (4.8 mL) under nitrogen is degassed, heated up to 50° C. and stirred at this temperature for 2 days, during which additional tris(dibenzylideneacetone)dipalladium(0) (22 mg, 0.0242 mmol), triphenylarsine (59 mg, 0.194 mmol) and copper(I) iodide (9 mg, 0.0484 mmol) are added. The resulting mixture is diluted with water (15 mL) and extracted with methylene chloride (3×20 mL), and the combined organic phase is dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting oil is diluted with ethyl acetate (25 mL) and extracted with aqueous hydrochloric acid (1M, 25 mL), and the aqueous phase is neutralized with sodium hydroxide (s), saturated with sodium chloride and extracted with methylene chloride (3×25 mL) containing a small amount of methanol. This combined organic phase is dried over anhydrous sodium sulfate and concentrated under reduced pressure, and the residue is recrystallized from ethyl acetate/hexane to give the title compound, mp 240-242° C. (dec.); MS (ESI+) for C15H12FN3O3 m/z 302 (M+H)+; [α]25D=−25 (c 0.94, DMSO).
