2,3-Dichloro-5,6-dicyano-1,4-benzoquinone → HCID 86694693, compound

HRID 475097Notes

Reaction equation

[N+:1]([C:4]1[CH:19]=[CH:18][C:7]2[N:8]([C:11]([O:13][C:14]([CH3:17])([CH3:16])[CH3:15])=[O:12])[CH:9]=[N:10][C:6]=2[CH:5]=1)([O-:3])=[O:2].[CH3:20][CH2:21][Mg+].[Br-].C(C1C(=O)C(Cl)=C(Cl)C(=O)C=1C#N)#N>C1COCC1>[CH2:20]([C:5]1[C:6]2[N:10]=[CH:9][N:8]([C:11]([O:13][C:14]([CH3:15])([CH3:16])[CH3:17])=[O:12])[C:7]=2[CH:18]=[CH:19][C:4]=1[N+:1]([O-:3])=[O:2])[CH3:21]

Participants

Conditions

Temperature: -15 °C

Procedure

To a solution of tert-butyl 5-nitro-1H-benzo[d]imidazole-1-carboxylate (150 g, 0.56 mol) in dry THF (1500 mL) was added EtMgBr (3.0 Min THF, 1.12 mol, 2 equiv.) dropwise at −15° C. The reaction mixture was stirred at −15° C. for 2 h. A solution of DDQ (129 g, 1.12 mol, 2 equiv.) in THF (120 mL) was added at −15° C., then the reaction mixture was warmed to RT and the stirring was continued for 2 h. The reaction mixture was quenched with water and extracted with EtOAc. The combined organic layers were washed with brine and then (Na2SO4), filtered, and concentrated. The crude material was purified by SiO2 chromatography eluting with 10% EtOAc/hexane to afford tert-butyl 4-ethyl-5-nitro-1H-benzo[d]imidazole-1-carboxylate (20 g, 12% yield) as a yellow solid.

Workup

temperaturethe reaction mixture was warmed to RT
waitthe stirring was continued for 2 h
customThe reaction mixture was quenched with water
extractionextracted with EtOAc
washThe combined organic layers were washed with brine
filtration(Na2SO4), filtered
concentrationconcentrated
customThe crude material was purified by SiO2 chromatography
washeluting with 10% EtOAc/hexane

Sources & evidence

ORD record: ord-bc7a01b52c224e83ad62145db5df038e
Source dataset: uspto-grants-2014_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08637537B2

Reaction notes

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