2-Methyltetrahydrofuran → HCID 118898597, compound

Participants

Reaction Steps

To a solution of 4-iodo-2-methyl-2H-pyrazole-3-carboxylic acid methyl ester (8.1 g, 30.45 mmol) in THF (anhydrous, 60 mL) was added isopropyl magnesium chloride (16.5 mL, 16.5 mmol) at −45° C. The solution turned from clear to light green-yellowish. Stirred at this temperature for 30 min, GC-MS (sample in CD3OD) indicated all halogen-metal exchange completed. To the mixture was added 1.9 N ZnCl2 in 2-MeTHF (9.62 mL, 18.3 mmol) dropwise and the reaction was warmed to room temperature. The mixture was stirred for 2 h, over which time it turned from clear yellowish to an opaque yellowish mixture. To this reaction was added Preparation 2 tert-butyl 3-[(4-bromobenzoyl)(3-methylpyridin-2-yl)amino]piperidine-1-carboxylate (12.04 g, 25.37 mmol) as a solid in one batch. The reaction temperature was then raised to 50° C., 1′-bis(di-tert-butylphosphino)ferrocene palladium dichloride (166 mg, 0.254 mmol) was added. The reaction was then stirred at 60° C. for 2 h then cooled to room temperature. The reaction was quenched with water and extracted 3× EtOAc. The organic layer was dried and concentrated. Purification was performed by Combiflash ISCO column (220 g) 0-75% EtOAc/heptane to isolate the desired title compound (12.8 g, 78%).

Provenance & Evidence