Potassium Carbonate → Methyl 3-methoxy-4-(6-nitrobenzimidazol-1-ylmethyl)benzoate

HRID 275138Notes

Reaction equation

HRID 275138 reaction equation
[N+:1]([C:4]1[CH:5]=[CH:6][C:7]2[NH:11][CH:10]=[N:9][C:8]=2[CH:12]=1)([O-:3])=[O:2].Br[CH2:14][C:15]1[CH:24]=[CH:23][C:18]([C:19]([O:21][CH3:22])=[O:20])=[CH:17][C:16]=1[O:25][CH3:26].C(=O)([O-])[O-].[K+].[K+]>C(C(C)=O)C>[CH3:26][O:25][C:16]1[CH:17]=[C:18]([CH:23]=[CH:24][C:15]=1[CH2:14][N:9]1[C:8]2[CH:12]=[C:4]([N+:1]([O-:3])=[O:2])[CH:5]=[CH:6][C:7]=2[N:11]=[CH:10]1)[C:19]([O:21][CH3:22])=[O:20]

Participants

5

Procedure

A solution of 6-nitrobenzimidazole (2.0 g.) and methyl 4-bromomethyl-3-methoxybenzoate (B) (3.5 g.) in methyl ethyl ketone (61 ml.) was treated with potassium carbonate (1.9 g.) and then heated under reflux for 24 hours. The solvent was then evaporated. The residue was extracted with ethyl acetate and inorganic material removed by filtration. The filtrate was evaporated. The resultant residue was purified by flash chromatography on a 6×30 cm. silica gel column using 1:1 v/v hexane:ethyl acetate as the eluent to give methyl 3-methoxy-4-(6-nitrobenzimidazol-1-ylmethyl)benzoate (K) (1.07 g., 26%); NMR: 3.9 (s,3H, OCH3), 4.0(s,3H, OCH3), 5.7(s,2H, NCH2), 7.4(d, 1H, Ar), 7.8(d,1H, H4 -benzimidazole), 8.1(dd, 1H, H5 -benzimidazole), 8.6(br s,2H, H2,7 -benzimidazole).

Workup

  1. temperatureheated
  2. temperatureunder reflux for 24 hours
  3. customThe solvent was then evaporated
  4. extractionThe residue was extracted with ethyl acetate and inorganic material
  5. customremoved by filtration
  6. customThe filtrate was evaporated
  7. customThe resultant residue was purified by flash chromatography on a 6×30 cm

Sources & evidence

ORD record
ord-ecbfbf910ddf4aa1a213530dcbce141c
Source dataset
uspto-grants-1995_02
Patent number
US05391758

Reaction notes

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