Isobutyl iodide → (3R)-3-ethyl-6-fluoro-4-(4-methoxybenzoyl)-1-isobutyl-3,4-dihydroquinoxalin-2(1H)-one

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Reaction Conditions

Reaction Steps

To a stirred solution of (3R)-3-ethyl-6-fluoro-4-(4-methoxybenzoyl)-3,4-dihydroquinoxalin-2(1H)-one (see Example 8) (0.25 g, 0.76 mmol) in acetonitrile (6 mL) under nitrogen was added cesium carbonate (0.13 g, 0.40 mmol), potassium carbonate (0.055 g, 0.40 mmol) and 1-iodo-2-methylpropane (0.30 mL, 0.48 g, 2.6 mmol). The mixture was stirred at 74° C. for 12 h. The solvent was then evaporated, and the residue was partitioned between methylene chloride and water. The organic layer was separated, washed with water, dried over magnesium sulfate, and concentrated in vacuo. The product was purified via Biotage Horizon® (SiO2, gradient from 4% EtOAc/hexane to 38% EtOAc/hexane) to yield 0.10 g (35%) of (3R)-3-ethyl-6-fluoro-4-(4-methoxybenzoyl)-1-isobutyl-3,4-dihydroquinoxalin-2(1H)-one.

Provenance & Evidence