Pyridine → methyl 1-(4-methoxyphenyl)-1H-benzimidazole-6-carboxylate

HRID 452607Notes

Reaction equation

HRID 452607 reaction equation
[NH:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10]([O:12][CH3:13])=[O:11])=[CH:9][C:4]=2[N:3]=[CH:2]1.[CH3:14][O:15][C:16]1[CH:21]=[CH:20][C:19](B(O)O)=[CH:18][CH:17]=1.N1C=CC=CC=1>ClCCl.C([O-])(=O)C.[Cu+2].C([O-])(=O)C>[CH3:14][O:15][C:16]1[CH:21]=[CH:20][C:19]([N:3]2[C:4]3[CH:9]=[C:8]([C:10]([O:12][CH3:13])=[O:11])[CH:7]=[CH:6][C:5]=3[N:1]=[CH:2]2)=[CH:18][CH:17]=1

Participants

6

Reactant 3

HCID 1049PyridineHCID 201262(4-Methoxyphenyl)boronic acidHCID 178497374HCID 178497374, compound

Product 1

HCID 68664448methyl 1-(4-methoxyphenyl)-1H-benzimidazole-6-carboxylateYield 13%

Reagents, catalysts & solvents 2

HCID 8895Cupric acetateCatalystHCID 6344DichloromethaneSolvent

Procedure

A suspension of methyl 1H-benzimidazole-5-carboxylate (10.4 g, 58.8 mmol), (4-methoxyphenyl)boronic acid (17.9 g, 118 mmol), copper(II) acetate (16.0 g, 88.2 mmol), pyridine (9.54 mL, 118 mmol) and molecular sieves 4A (24.0 g) in dichloromethane (240 mL) was stirred at room temperature for 6 hr. The reaction mixture was filtered, and the filtrate was washed with 5% aqueous ammonia and saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (dichloromethane/ethyl acetate=5/1) and recrystallized from hexane/ethyl acetate to give the title compound (2.15 g, yield 13%) as colorless crystals.

Workup

  1. filtrationThe reaction mixture was filtered
  2. washthe filtrate was washed with 5% aqueous ammonia and saturated brine
  3. dry with materialdried over anhydrous magnesium sulfate
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was purified by silica gel column chromatography (dichloromethane/ethyl acetate=5/1)
  6. customrecrystallized from hexane/ethyl acetate

Sources & evidence

ORD record
ord-60e62dab18e345f588baaf8dd48112a6
Source dataset
uspto-grants-2013_07
Patent number
US08492378B2

Reaction notes

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