Synthesis
GENERAL METHOD: 2-Amino-5-bromophenol (400 mg, 3.67 mmol) and N-cyano-4-methyl-N-phenylbenzenesulfonamide (998 mg, 3.67 mmol) were dissolved in THF (6 mL), and a hexane solution (3.67 mL, 3.67 mmol) of 1M LiHMDS was slowly added at 0°C. The reaction mixture was stirred at 0°C to room temperature for 1 hour. Subsequently, the reaction mixture was poured into ice water and stirring was continued for 15 min. The reaction mixture was extracted with EtOAc and the organic layer was separated. The organic layer was washed with saturated brine solution and then dried with anhydrous Na2SO4. After filtration, the organic layer was concentrated under reduced pressure. The crude product was purified by silica gel column chromatography to give pure 2-amino-6-bromobenzoxazole in 90% yield (471 mg).
References
[1] Synlett, 2015, vol. 26, # 7, p. 897 - 900
