To a solution of 4-[2-(3-benzofuran-2-yl-4-bromobut-2-enoylamino)ethoxy]benzoic acid methyl ester (300 mg, 0.654 mmol)) in dry DMF (4 ml), potassium carbonate (180 mg, 1.31 mmol) and azetidine hydrochloride (41 mg, 0.719 mmol) were added. The reaction mixture was stirred for 4 h at 50° C. The reaction mixture was diluted with ethyl acetate and the resulting suspension was washed with water and brine. After drying the organic phase over sodium sulfate, the solvent was removed under vacuum and the residue was purified by flash chromatography, using mixture of DCM/MeOH (9.5/0.5) as eluent to give 4-[2-(4-azetidin-1-yl-3-benzofuran-2-yl-but-2-enoylamino)ethoxy]benzoic acid methyl ester.
