Sodium Carbonate → tert-butyl 5,6-dihydro-4-(4-nitrophenyl)pyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a 25-mL RB flask, equipped with a condensor, was added tert-butyl 4-{[(trifluoromethyl)sulfonyl]oxy}-3,6-dihydro-1(2H)-pyridinecarboxylate (1.0 g), 4-nitrophenylboronic acid (0.71 g), sodium carbonate (0.430 mL of 2M solution), lithium chloride (0.382 g), tetrakis(triphenylphosphine)-palladium(0) (0.173 g) and ethylene glycol dimethyl ether (10 mL). The reaction mixture was flushed with Argon three times, then the reaction mixture was heated to 100° C. for 3 hrs. After cooling to room temperature, the reaction mixture was diluted with methylene chloride (30 mL) and water (30 mL) and the organic layer was separated. The aqueous layer was extracted with methylene chloride (3×20 mL) and the combined organic extracts were washed with sat NH4Cl (20 mL) and brine (20 mL), dried over MgSO4 and concentrated under reduced pressure. The residue was purified by chromatography (6:1=hexane:ethyl acetate with 1% NH3) to afford the product (0.55 g, 59.9%) as a yellow oil. The compound is not stable at room temperature and should be used as promptly as practical: 1H NMR (400 MHz, CDCl3) δ 8.20 (d, 2H, J=8.6 Hz), 7.51 (d, 2H, J=8.6 Hz), 6.24 (m, 1H), 4.13 (m, 2H), 3.67 (apparent t, 2H, J=5.5 Hz), 2.55 (m, 2H), 1.49 (s, 9H).

Provenance & Evidence