Bromine → 2-(S)-(2-Acetoxymethyl-4-amino-5-bromo-3-methyl-benzyl)-succinic acid diethyl ester

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Reaction Steps

2-(S)-(2-Acetoxymethyl-4-amino-3-methyl-benzyl)-succinic acid diethyl ester (7.6 g, 21 mmol) was dissolved in acetic acid (100 mL). Sodium acetate (4.2 g, 51 mmol) was added to the solution. Reaction vessel was placed in a cool water bath to control reaction exotherm. Bromine (1.1 mL, 22 mmol) was added to the mixture in one portion. Reaction stirred at ambient temperature for 10 minutes. Mixture was poured into 1N aqueous sodium thiosulfate solution (400 mL). Material was extracted twice with ethyl acetate. Organic phase was washed successively with water and brine. Organic was dried (magnesium sulfate), filtered and concentrated in vacuo. Silica gel chromatography (ethyl acetate-hexanes) afforded the desired product in 77% yield as an amber oil. MS m/e (M−H)−=440.0, 442.0.

Provenance & Evidence