General procedure for the synthesis of ((5-thiazolyl)methyl)-(4-nitrophenyl)carbonate (compound 9) from 5-hydroxymethylthiazole (compound 8, 17 mmol) and bis(p-nitrophenyl)carbonate (compound 7, 19 mmol): compound 7 was added to a dichloromethane (DCM, 40 mL) solution of compound 8, followed by triethylamine (26 mmol) . The reaction mixture was stirred at room temperature for 12 h. After completion of the reaction it was concentrated under reduced pressure. The concentrated mixture was diluted with ethyl acetate (EtOAc) and washed sequentially with saturated aqueous sodium carbonate (Na2CO3) solution, water and brine. After washing, the organic solvent was removed under reduced pressure. The residue was purified by fast column chromatography (silica gel as stationary phase, eluent ratio hexane/ethyl acetate=1/1) to give the final compound 9 (4.7 g).
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