Bromine → Diethyl 2-bromo-3,4,5-trimethoxyphenylphosphonate

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Reaction Steps

A solution of bromine (10 mmol) in 10 mL of acetic acid is added dropwise to a solution of ester 11 (10 mmol) in 10 mL of acetic acid cooled by an ice water bath. After the red color of the resulting mixture is discharged, the mixture is poured into saturated NaHCO3 (100 mL) and extracted with ethyl acetate (3×100 mL). The combined organic phases are washed with 100 mL portions of 5% NaHCO3 until no further gas evolution is apparent. The organic phases are then washed with brine (100 mL), dried over anhydrous MgSO4, and concentrated in vacuo. The mixture is purified by flash chromatography to give the product as a pale yellow solid.

Provenance & Evidence