Cesium carbonate → Methyl 4-bromo-1,1'-biphenyl-2-carboxylate

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Reaction Steps

To methyl 5-bromo-2-iodobenzoate (4.41 g, 13 mmol), phenylboronic acid (1.6 g, 13 mmol), potassium carbonate (3.6 g, 26 mmol), and cesium carbonate (4.2 g, 13 mmol) in DMF (50 mL, sparged with nitrogen) was added palladium(0) tetrakis(triphenylphosphine) (751 mg, 0.65 mmol). The reaction was refluxed 16 h, cooled and washed with water, 1N hydrochloric acid, saturated sodium bicarbonate, and saturated sodium chloride. The organic layer was dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (5% ethyl acetate/hexane) to yield methyl 4-bromo-1,1′-biphenyl-2-carboxylate (1.3 g). To methyl 4-bromo-1,1′-biphenyl-2-carboxylate (500 mg, 1.72 mmol) and Pd(dppf)Cl2—CH2Cl2 (70 mg, 0.086 mmol) in THF (5 mL) was added 1M neopentyl magnesium chloride (5 mL, 5 mmol) slowly at room temperature. The reaction was stirred overnight and then quenched with water. The reaction was diluted in ethyl acetate, and the resulting brown solid was filtered away. The organic layer was washed with water, 1N hydrochloric acid, saturated sodium bicarbonate, and saturated sodium chloride. The organic layer was dried over sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by flash chromatography (1% ethyl acetate/hexane) to yield a yellow solid (200 mg).

Provenance & Evidence