Lithium Chloride → Methyl 4-(2-ethoxyvinyl)-1-(4-fluorobenzyl)-1H-pyrrolo[2,3-c]pyridine-5-carboxylate

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Reaction Conditions

Reaction Steps

To a solution of methyl 1-(4-fluorobenzyl)-4-{[(trifluoromethyl)sulfonyl]oxy}-1H-pyrrolo[2,3-c]pyridine-5-carboxylate (2 g, 4.62 mmol) in DMF (27 mL) was added lithium chloride (0.59 mg, 13.88 mmol). Dry nitrogen was bubbled through the mixture for for 10 min, and then dichlorobis(triphenylphosphine)palladium(II) (0.16 g, 0.23 mmol) was added. The mixture was heated to 79° C., and a solution of ethoxyvinyl tributyltin (mixture of isomers: 1,2-E:1,2-Z:1,1=1:0: 0.97:0.18) [prepared according to A. Leusik, H. A. Budding, J. W. Marsman, J. Organomet. Chem., 1967, 9, 285-294] (1.82 g, 5.08 mmol) in DMF (23 mL). The resulting mixture was stirred for 9 h at 70° C. under nitrogen atmosphere. It was quenched with saturated sodium chloride and filtered to remove solid precipitate then concentrated. Purification by flash chromatography (Biotage) over silica gel (1:1 to 1:3, hexane/ethyl acetate) afforded the title product as brown glue (1.46 g, 89.2% yield). LCMS (APCl, M+H+): 355.2.

Provenance & Evidence