Methyl 6-chloro-5-methylpyridine-3-carboxylate → Methyl 5-methyl-6-(3,3,3-trifluoropropyl)nicotinate

Participants

Reaction Conditions

Reaction Steps

To a suspension of zinc powder (2.49 g, 38.1 mmol) in THF (15 mL), 1,2-dibromoethane (0.21 g, 1.1 mmol) and trimethylsilyl chloride (0.12 g, 1.1 mmol) are added. After stirring at rt for 20 minutes, 1,1,1-trifluoro-3-iodopropane (6.10 g, 27.2 mmol) is added, and the mixture is stirred at 55° C. for 1 hour to give a solution of (3,3,3-trifluoropropyl)zinc iodide in THF. To a mixture of methyl 6-chloro-5-methylnicotinate (2.02 g, 10.9 mmol, Step-1) and tetrakis(triphenylphosphine)palladium(0) (1.01 g, 0.87 mmol) in DMF (15 mL) is added the zinc reagent, and the mixture is stirred at 55° C. for 12 hours. After cooling to rt, the mixture is poured onto water (100 mL), and the aqueous layer is extracted with EtOAc (30 mL×2). The combined organic layer is dried over sodium sulfate, and after filtration, the filtrate is concentrated in vacuo. The residue is purified by column chromatography on silica-gel eluting with n-hexane/EtOAc (5:1 to EtOAc only) to give 2.32 g (86% yield) of the title compound as an orange solid.

Provenance & Evidence