Ethanol → 7-(benzyloxy)-5-bromo-1-methyl-1H-benzo[d]imidazole

HRID 2209018Notes

Reaction equation

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

Participants

Conditions

Temperature: 90 °C

Procedure

To a solution of 2-(benzyloxy)-4-bromo-N-methyl-6-nitroaniline 2.50 (770 mg, 2.25 mmol) in ethanol (12 mL) and formic acid (15 mL) was added iron (630 mg, 11.27 mmol) and heated at 90° C. at 4 h and LCMS shows still lot of starting material present. 500 mg of iron was added and the mixture was heated at 90° C. overnight. The reaction mixture was concentrated, diluted with water and acidified to pH˜7 with sat'd NaHCO3 and then the aqueous layer was extracted with EtOAc (3×). Combined organic layer were then washed successively with water and brine and dried over anhydrous magnesium sulfate. The residue was purified by flash column chromatography (SiO2, 100% EtOAc) to give 7-(benzyloxy)-5-bromo-1-methyl-1H-benzo[d]imidazole 2.51.

Workup

temperaturethe mixture was heated at 90° C. overnight
concentrationThe reaction mixture was concentrated
additiondiluted with water
extractionthe aqueous layer was extracted with EtOAc (3×)
washCombined organic layer were then washed successively with water and brine
dry with materialdried over anhydrous magnesium sulfate
customThe residue was purified by flash column chromatography (SiO2, 100% EtOAc)

Sources & evidence

ORD record: ord-49cdb23d8a8d49d9b80492897ec8c96a
Source dataset: uspto-grants-2016_06
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09376441B2

Reaction notes

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