Hydrogen Bromide → Methyl 5-bromo-2-fluoro-3-(2-oxo-1-pyrrolidinyl)benzoate

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Reaction Conditions

Reaction Steps

To a solution of methyl 5-amino-2-fluoro-3-(2-oxo-1-pyrrolidinyl)benzoate (D150) (650 mg, 2.6 mmol, 1 equiv) in a 48% aqueous HBr solution at 0° C. was added NaNO2 portionwise and the resulting mixture was stirred at 0° C. for 30 min. CuBr (260 mg, 1.82 mmol, 0.7 equiv) in a 48% aqueous HBr solution (1 ml) was added and the resulting mixture stirred at 90° C. for 1 h then cooled to room temperature and partitioned between H2O and AcOEt. The two layers were separated and the organic phase was dried over MgSO4 and concentrated in vacuo. Purification of the residue by flash chromatography on silica gel (iso-hexane/AcOEt: 2/1) gave methyl 5-bromo-2-fluoro-3-(2-oxo-1-pyrrolidinyl)benzoate (D156) (145 mg, 18%) as a white solid. [M+H]+=318.1, RT=2.51 min.

Provenance & Evidence