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

HRID 2200771Notes

Reaction equation

HRID 2200771 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([OH:12])[C:5]2[N:6]=[CH:7][CH:8]=[N:9][C:10]=2[CH:11]=1.N1C=CN=C1.[Si:18](Cl)([C:21]([CH3:24])([CH3:23])[CH3:22])([CH3:20])[CH3:19]>C(Cl)Cl>[Br:1][C:2]1[CH:11]=[C:10]2[C:5]([N:6]=[CH:7][CH:8]=[N:9]2)=[C:4]([O:12][Si:18]([C:21]([CH3:24])([CH3:23])[CH3:22])([CH3:20])[CH3:19])[CH:3]=1

Participants

5

Reactant 3

HCID 795ImidazoleHCID 28928tert-Butyldimethylsilyl chlorideHCID 1366295117-Bromoquinoxalin-5-ol

Product 1

HCID 904114467-Bromo-5-((tert-butyldimethylsilyl)oxy)quinoxaline

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

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).

Workup

  1. concentrationconcentrated under reduced pressure
  2. custompurified by medium pressure silica gel chromatography (0 to 20% EtOAc/hexanes gradient)

Sources & evidence

ORD record
ord-f728c00d18cf4115ab597d8aa352d8cf
Source dataset
uspto-grants-2016_06
Patent number
US09359380B2

Reaction notes

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