Imidazole → 7-Bromo-5-((tert-butyldimethylsilyl)oxy)quinoxaline

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Reaction Steps

As shown in step 6-vi of Scheme 6, a solution of 7-bromoquinoxalin-5-ol (2.0 g, 8.89 mmol) in DCM (20 mL) was added imidazole (1.82 g, 26.7 mmol) and tert-butyldimethylsilyl chloride (1.34 g, 1.65 mL, 8.89 mmol). The reaction mixture was stirred overnight at RT, concentrated under reduced pressure, and purified by medium pressure silica gel chromatography (0 to 20% EtOAc/hexanes gradient) to provide 7-bromo-5-((tert-butyldimethylsilyl)oxy)quinoxaline (compound 1018) as a colorless oil: 1H-NMR (300 MHz, CDCL3) δ 8.69 (q, J=1.8 Hz, 2H), 7.80 (d, J=2.1 Hz, 1H), 7.22 (d, J=2.1 Hz, 1H), 0.96 (s, 9H), 0.81 (s, 7H).

Provenance & Evidence