Formic Acid → 1-Methyl-1H-benzimidazole-5-carboxylic acid

HRID 626241

Reaction equation

HRID 626241 reaction equation
[NH2:1][C:2]1[CH:3]=[C:4]([CH:8]=[CH:9][C:10]=1[NH:11][CH3:12])[C:5]([OH:7])=[O:6].[CH:13](O)=O>O>[CH3:12][N:11]1[C:10]2[CH:9]=[CH:8][C:4]([C:5]([OH:7])=[O:6])=[CH:3][C:2]=2[N:1]=[CH:13]1

Participants

4

Reactant 2

HCID 284Formic AcidHCID 115211443-Amino-4-(methylamino)benzoic acid

Product 1

HCID 49130631-Methyl-1H-benzimidazole-5-carboxylic acidYield 84%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
85 °C

Procedure

To a stirred solution of 3-amino-4-(methylamino)benzoic acid (9 g, 1.0 eq) in 50 mL water, was added 50 mL formic acid and heated at 85° C. overnight. The mixture was cooled, concentrated in vacuo, and dissolved in water. Then 2N HCl was added to adjust pH to 1-3. The suspension was filtered and washed with water to give the product (9.7 g, 84%). 1H NMR (400 MHz, DMSO-d6) δ 9.48 (s, 1H), 8.37 (s, 1H), 8.12 (d, J=8.8 Hz, 1H), 8.00 (d, J=8.8 Hz, 1H), 4.06 (s, 3H).

Workup

  1. temperatureThe mixture was cooled
  2. concentrationconcentrated in vacuo
  3. dissolutiondissolved in water
  4. additionThen 2N HCl was added
  5. filtrationThe suspension was filtered
  6. washwashed with water

Sources & evidence

ORD record
ord-506f69e4209d47d4b3dc23f790744a31
Source dataset
uspto-grants-2016_04
Patent number
US09309211B2

Linked notes

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