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With 1-methyl-1H-imidazole; sodium hydrogencarbonate; In dichloromethane; at 40℃;
Step B - Methyl 5-(5;6-dichbro-1Mbenzimidazoi-1-yf)-3-hydroxy-2~ thiophenecarboxyiateTo a solution of 5,6-dichloro-1 No.-benzimidazoIe (1.26 g, 8.72 mmoi) and methyl 2-ch.oro-3-oxo-2,3-dihydro-2-thiorhohe?ecarboxy.afe (1.49 g, 7.73 mmoi) in DCM (34 mL) was added NaHCO3 (1.70 g, 20.2 mmof) and M methylfmidazole (0.830 g, 10.1 mmo.) and heated at 400C overnight, The reaction mixture was cooled to it and DCM and wafer were added. The layers were separated and the aqueous layer was extracted with DCM. The combined organic layers were dried over Na2SO4 and filtered. S'lca was added to the filtrate and the volstiies were evaporated under reduced pressure and the residue was purified by flash column chromatography (0 to 100% EtOAc:hexane) to afford 1.5 g (65%) of the title compound. 1H NMR (300 MHz, DMSO-£/6) delta 10,88 (s, 1H), 8.76 (s; 1H), S.10 (s, 1H), 7.99 (S1 IH), 7.17 (s, 1H), 3.79 (S, 3H). MS (ESI): 343 {M+Hf.