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

Participants

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 (250 mg, 0.85 mmol), (S)-methyl 6-bromo-5-cyclobutoxy-2-methyl-3,4-dihydroquinoline-1(2H)-carboxylate (317 mg, 0.89 mmol), sodium carbonate (150 mg, 1.42 mmol), [1,1′-bis(diphenylphosphino)ferrocene]dichloropalladium(II) (58 mg, 0.18 mmol), 1,4-dioxane (10 mL), and water (2 mL). The resulting mixture stirred overnight at 100° C. in an oil bath. After cooling to room temperature, the reaction mixture was poured into 10 mL of water and the layers were separated. The aqueous layer was extracted with ethyl acetate (3×10 mL). The organic layers were combined, 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 (200 mg, 52%) as yellow oil. MS (ESI, pos. ion) m/z 342 [M+H]+.

Provenance & Evidence