Cesium carbonate → (S)-isopropyl 4-acetyl-7-(1-(2-hydroxyethyl)-1H-pyrazol-4-yl)-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate

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Reaction Conditions

Reaction Steps

A mixture of (S)-isopropyl 4-acetyl-7-bromo-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (0.050 g, 0.141 mmol), 2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)ethanol (0.050 g, 0.211 mmol), chloro(2-dicyclohexylphosphino-2′,4′,6′-tri-i-propyl-1,1′-biphenyl)(2′-amino-1,1′-biphenyl-2-yl) palladium(II) (XPhos 2nd generation precatalyst) (5.54 mg, 7.04 μmol), and cesium carbonate (0.138 g, 0.422 mmol) in 1,4-dioxane (2.0 mL) and water (0.40 mL) was stirred in the microwave at 100° C. for 1 h. The reaction mixture was filtered through Celite and concentrated to afford a yellow oil. This material was purified via column chromatography on silica gel (Biotage 25 g column, gradient elution with 0-10% methanol-ethyl acetate) to afford (S)-isopropyl 4-acetyl-7-(1-(2-hydroxyethyl)-1H-pyrazol-4-yl)-3-methyl-3,4-dihydroquinoxaline-1(2H)-carboxylate (0.052 g, 96%) as an off-white solid.

Provenance & Evidence