Ethyl Acetate → 2-Bromo-6-(8-tert-butyl-5-oxo-2,3-dihydro-5H-benzo[f][1,4]oxazepin-4-yl)benzaldehyde

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Reaction Conditions

Reaction Steps

8-tert-Butyl-3,4-dihydro-2H-benzo[f][1,4]oxazepin-5-one (600 mg, 2.74 mmol, 2,6-Dibromo-benzaldehyde (3.62 g, 5eq), Xanthphos (71 mg, 0.045eq), and cesium carbonate (1.25 g, 1.4 eq) were taken up in dioxane (5.3 mL) and a stream of Argon gas was bubbled through the mixture for 10 minutes. The catalyst Pd(dba)2 (47 mg, 0.03 eq) was added and the resulting mixture was placed under argon and stirred at 100° C. for three hours. By TLC, the reaction was complete and after cooling the mixture to room temperature, ethyl acetate (150 mL) and water (50 mL) were added and the layers were partitioned and separated. The organic layer was further washed with water (3×50 mL) and finally washed with brine (1×50 mL) before it was dried over magnesium sulfate, filtered and concentrated. Purification by column chromatography on silica gel eluting with a gradient of 5% ethyl acetate to 30% ethyl acetate afforded the title compound as an off-white powder (793 mg) (M+H)+=404.

Provenance & Evidence