Sodium Carbonate → (S)-methyl 5-cyclobutoxy-2-methyl-6-(1H-pyrazol-4-yl)-3,4-dihydroquinoline-1 (2H)-carboxylate

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Reaction Conditions

Reaction Steps

A 100-mL round-bottom flask was charged with tert-butyl 4-(tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole-1-carboxylate (0.250 g, 0.85 mmol), (S)-methyl 6-bromo-5-cyclobutoxy-2-methyl-3,4-dihydroquinoline-1(2H)-carboxylate (0.317 g, 0.89 mmol), sodium carbonate (0.150 g, 1.42 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) dichloromethane adduct (0.070 g, 0.085 mmol), 1,4-dioxane (10 mL), and water (2 mL). The resulting mixture stirred overnight at 100° C., was cooled to room temperature, and water (10 mL) was added. The aqueous layer was separated and extracted with ethyl acetate (3×10 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified via column chromatography on silica gel (eluting with 5:1, ethyl acetate/petroleum ether) to afford (S)-methyl 5-cyclobutoxy-2-methyl-6-(1H-pyrazol-4-yl)-3,4-dihydroquinoline-1(2H)-carboxylate (0.200 g, 52%) as yellow oil. MS (ESI, pos. ion) m/z 342 [M+H]+.

Provenance & Evidence