6-Bromo-2-methylbenzodoxazole

Synthesis

Using 2-amino-5-bromophenol (561 mg, 3.00 mmol) and triethyl orthoacetate (656 μL, 3.6 mmol) as the raw material, 1,3-dibromo-5,5-dimethylglycolonide (17.2 mg, 0.060 mmol) was added as a catalyst. The reaction mixture was stirred at room temperature for 10 min. After completion of the reaction, the reaction mixture was extracted with ethyl acetate (50 mL × 2). The organic layers were combined, washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was removed by distillation under reduced pressure to obtain the crude product. The crude product was purified by silica gel column chromatography using ethyl acetate/hexane (1:4, v/v) as eluent to afford 6-bromo-2-methylbenzoxazole (560 mg, 88.5% yield).

References

[1] Journal of Medicinal Chemistry, 2015, vol. 58, # 18, p. 7241 - 7257
[2] Patent: JP2016/79108, 2016, A. Location in patent: Paragraph 0063
[3] Patent: WO2012/151525, 2012, A1. Location in patent: Page/Page column 128
[4] Patent: US2012/289496, 2012, A1. Location in patent: Page/Page column 113