Picolinic acid → Diethyl 2-(5-bromopyridin-2-yl)malonate

Beteiligte Stoffe

Reaktionsschritte

A mixture of 5-bromo-2-iodo-pyridine (56.8 g, 0.2 mol), malonic acid diethyl ester (64 g, 0.4 mol), CuI (3.8 g, 0.02 mol), Cs2CO3 (195.5 g, 0.6 mol) and pyridine-2-carboxylic acid (2.46 g, 0.04 mol) in 1,4-dioxane (400 mL) was stirred at 70 degrees Celsius under N2 for 24 hours. After cooling to room temperature, the solid was filtered and the solvent was evaporated. The residue was dissolved in ethyl acetate (400 mL) and washed with water, brine, dried over Na2SO4, filtered, concentrated in vacuo, the crude product was purified by flash chromatography (Petroleum Ether:EtOAc=20:1) to obtain an oil (31.6 g, 50%). MS: calc'd 316 (MH+), exp 316 (MH+). 1H NMR (d6-DMSO, 400 MHz), 8.68 (d, 1H, J=2.4 Hz), 8.11 (dd, 1H, J=2.4, 8.4 Hz), 7.45 (d, 1H, J=8.4 Hz), 5.16 (s, 1H), 4.20-4.07 (m, 4H), 1.18 (t, J=8.4 Hz, 6H).

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