Citric Acid → 4-(2-Bromo-5-fluorophenyl)-2-hydroxy-4-methylvaleric acid-methyl ester

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Reaction Steps

A solution of 0.9 g (2.13 mmol) of 2-benzoyl-4-(2-bromo-5-fluorophenyl)-4-methylvaleric acid-methyl ester in 50 ml of MeOH is mixed with 1.47 g (10.6 mmol) of potassium carbonate and stirred for 3 hours at room temperature. The batch is acidified (pH 3) with 10% sulfuric acid, and it is extracted with ethyl acetate. The combined extracts are washed with saturated NaCl, dried (Na2SO4) and concentrated by evaporation in a vacuum. The residue is taken up in 8 ml of DMF and stirred with 1.92 g (5.9 mmol) of cesium carbonate and 0.38 ml (5.9 mmol) of methyl iodide for 3 hours at room temperature. The batch is mixed with 10% citric acid and extracted with MTBE. The organic phase is washed with saturated NaCl, dried (Na2SO4) and concentrated by evaporation in a vacuum. Column chromatography on silica gel with hexane-ethyl acetate yields 250 mg of product.

Provenance & Evidence