Trimethyl orthoformate → 1H-Benzimidazole-5-carboxylic acid, 7-iodo-, methyl ester

HRID 446227Notes

Reaction equation

HRID 446227 reaction equation
[CH3:1][O:2][C:3](=[O:13])[C:4]1[CH:9]=[C:8]([I:10])[C:7]([NH2:11])=[C:6]([NH2:12])[CH:5]=1.[CH:14](OC)(OC)OC>C1COCC1.C1(C)C=CC(S(O)(=O)=O)=CC=1>[CH3:1][O:2][C:3]([C:4]1[CH:9]=[C:8]([I:10])[C:7]2[N:11]=[CH:14][NH:12][C:6]=2[CH:5]=1)=[O:13]

Participants

5

Reactant 2

HCID 9005Trimethyl orthoformateHCID 67512100Methyl 3,4-diamino-5-iodobenzoate

Product 1

HCID 596277711H-Benzimidazole-5-carboxylic acid, 7-iodo-, methyl esterYield 45.1%

Reagents, catalysts & solvents 2

HCID 6101p-Toluenesulfonic acidCatalystHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 3,4-diamino-5-iodo-benzoic acid methyl ester (1.68 g, 5.75 mmol) in THF (20 mL) was added trimethyl orthoformate (1.26 mL, 11.5 mmol) and 4-toluenesulfonic acid (11 mg, 0.057 mmol). The mixture was stirred at room temperature overnight, then partitioned between ethyl acetate and water. The organic layer was separated, dried over MgSO4, filtered and concentrated under reduced pressure to give 783 mg (45%) of 7-Iodo-3H-benzoimidazole-5-carboxylic acid methyl ester, MS (M+H)=303.

Workup

  1. custompartitioned between ethyl acetate and water
  2. customThe organic layer was separated
  3. dry with materialdried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-1266960ff17c4bc599b574c5960c6c30
Source dataset
uspto-grants-2013_07
Patent number
US08476457B2

Reaction notes

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