Ethyl Acetate → tert-butyl 4-(1H-imidazol-2-yl)-3,6-dihydropyridine-1(2H)-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-bromo-1H-imidazole (1.2 g, 8.16 mmol), tert-butyl 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (3.0 g, 9.70 mmol), sodium carbonate (2.1 g, 19.8 mmol), and [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane adduct (0.120 g, 0.16 mmol) in 1,4-dioxane (30 mL) and water (10 mL) stirred overnight at 100° C. The reaction mixture was cooled to room temperature, poured into ethyl acetate (100 mL), washed with water (30 mL) and brine (30 mL), dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified via column chromatography on silica gel (eluting with 25% ethyl acetate-petroleum ether) to afford tert-butyl 4-(1H-imidazol-2-yl)-5,6-dihydropyridine-1(2H)-carboxylate (0.300 g, 15%) as a light yellow solid. MS (ESI, pos. ion) m/z 250 [M+H]+.

Provenance & Evidence