Ethanol → Methyl 3,5-dibromo-4-mercaptophenylacetate

Participants

Reaction Steps

A solution of ethyl 3,5-dibromo-4-(N,N-dimethylcarbamoylthio)phenylacetate (8 g, 0.018 mol), from Preparation D, in 100 mL of 10% aqueous sodium hydroxide and 10 mL ethanol was heated at reflux for 20 hrs under a nitrogen atmosphere. The reaction mixture was cooled and neutral impurities extracted with ethyl acetate. The aqueous phase was acidified with 6N HCl and extracted twice with ethyl acetate. The combined extracts were washed with water and saturated sodium chloride solution, dried (Na2SO4), and the solvent removed on a rotary evaporator. The residue was dissolved in methanol and treated with 3 mL of concentrated sulfuric acid and heated at reflux temperature for 3 hrs. The reaction mixture was cooled and concentrated. The residue was diluted with ethyl acetate, washed with water and brine, dried (Na2SO4), and the solvent removed on a rotary evaporator. The residue was purified by flash chromatography (silica gel, 5% acetone/hexane) to obtain methyl 3,5-dibromo-4-mercaptophenylacetate (3.5 g, 0.01 mol, 57% yield), MP: 63.5°-65° C.

Provenance & Evidence