Synthesis
Step 1. General procedure for the synthesis of 2-amino-3-fluorophenol from 3-fluoro-2-nitrophenol: Stannous chloride dihydrate (0.724 g, 3.18 mmol) was added to a solution of tetrahydrofuran (THF, 5.0 mL) of 3-fluoro-2-nitrophenol (0.100 g, 0.636 mmol, SynQuest), followed by water ( 5.0 mL). The reaction mixture was heated to 80 °C and maintained for 40 min. After the reaction was completed, it was cooled to room temperature and the reaction mixture was diluted with ethyl acetate and saturated sodium bicarbonate solution. The insoluble material was removed by filtration and the organic and aqueous layers were separated. The aqueous layer was extracted three times with ethyl acetate. The combined organic extracts were washed with brine, dried over anhydrous sodium sulfate, filtered and concentrated to give the crude product 2-amino-3-fluorophenol (65 mg, 80% yield), which could be used in the subsequent reaction without further purification.LCMS (M + H)+: 128.0.
References
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[5] Patent: US6262113, 2001, B1