Imidazole → 3-Hydroxy-5-imidazol-1-yl-thiophene-2-carboxylic acid methyl ester

Participants

Reaction Steps

Imidazole (710 mg, 10.4 mmol, 2 Eq.) and 2-Chloro-3-oxo-2,3-dihydro-thiophene-2-carboxylic acid methyl ester (1.0 g, 5.19 mmol, 1.0 Eq.) were dissolved in anhydrous DCM (25 mL) and stirred at ambient temperature for 18 hours. The crude reaction mixture was partitioned between EtOAc (50 mL) and brine (50 mL), The aqueous phase was extracted with EtOAc (3×20 mL) and the combined organic extracts washed with brine (1×10 mL), dried (Na2SO4) and concentrated in vacuo. The residue was purified by column chromatography (5% MeOH/DCM) and recrystallised from EtOAc/hexane to give the sub-title compound as a yellow powder (692 mg, 3.09 mmol 59%); 1H NMR (400 MHz, d-6 DMSO) δ 3.77 (3H, s), 7.02 (1H, s), 7.14 (1H, d), 7.74 (1H, d), 8.28 (1H, d), 10.82 (1H, br s).

Provenance & Evidence