Methyl chloroacetate → 7-Bromobenzofuran-2-carboxylic acid

Participants

Reaction Conditions

Reaction Steps

10 g (49.75 mmol) of 3-bromo-2-hydroxybenzaldehyde and 1.84 g (4.97 mmol) of tetra-N-butylammonium iodide are, together with 27.5 g (199.0 mmol) of anhydrous potassium carbonate, initially charged. 24.3 g (223.86 mmol) of methyl chloroacetate are added. The reaction mixture is heated at 130° C. for 4 h and then cooled to 0° C. using an ice bath. 100 ml of THF and 16.75 g (298.5 mmol) of potassium hydroxide in 100 ml of water are added, the mixture is then stirred at 40° C. for 4 h. The solvent is removed under reduced pressure. The residue is diluted with water and acidified with conc. hydrochloric acid. The product is purified on silica gel 60 (mobile phase: toluene/ethyl acetate/acetic acid 40:10:1). The solvent is removed under reduced pressure. Any last solvent residues are finally removed under high vacuum. Fine purification is carried out by preparative HPLC. 303 mg (2.5% of theory) of the title compound are isolated.

Provenance & Evidence