Cesium carbonate → Tert-butyl 4-(6-(methoxycarbonyl)pyridin-3-yl)piperazine-1-carboxylate

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Reaction Conditions

Reaction Steps

To a flask containing methyl 5-bromopicolinate 49-1 (1.48 g, 6.85 mmol), tert-butyl piperazine-1-carboxylate 49-2 (1.53 g, 8.22 mmol), Pd2(dba)3 (315 mg, 0.34 mmol), BINAP (462 mg, 0.69 mmol) and Cs2CO3 (5.50 g, 17.20 mmol) under argon was added anhydrous toluene (30 mL). The mixture was stirred at 100° C. for 10 hours. After cooling to room temperature, the solvent was removed by rotary evaporation. The residue was redissolved in ethyl acetate (100 mL), washed with H2O and brine, dried over Na2SO4, and concentrated to dryness by rotary evaporation. The crude product was purified by silica gel flash chromatography, eluted with 5% methanol in dichloromethane to give tert-butyl 4-(6-(methoxycarbonyl)pyridin-3-yl)piperazine-1-carboxylate 49-3 as a yellow solid. MS m/z 322.1 (M+1)

Provenance & Evidence