Ethyl chloroformate → Tert-butyl ethyl (4-(thiophen-2-yl)-1,2-phenylene)dicarbamate

関与物質

反応手順

To a solution of tert-butyl (2-amino-4-(thiophen-2-yl)phenyl)carbamate (0.20 g, 0.69 mmol, 1.0 equiv.) in dichloromethane (4 mL) was added ethyl chloroformate (0.08 mL, 0.83 mmol, 1.2 equiv.), TEA (0.19 mL, 1.37 mmol, 2.0 equiv.) and DMAP (8 mg, 0.07 mmol, 0.1 equiv.) at 0° C. The reaction was warmed to room temperature and stirred for 16 h. The reaction was then diluted with dichloromethane and water. The organic layer was separated, washed with water and brine, dried over sodium sulfate, filtered and concentrated under reduced pressure. The crude material was purified on column chromatography (silica gel, 20% EtOAc/hexanes) to give tert-butyl ethyl (4-(thiophen-2-yl)-1,2-phenylene)dicarbamate (0.11 g, 44% yield).

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