O-Phenylenediamine → 1H-benzimidazole, 2-(4-methyl-2-pyridinyl)-

HRID 2354040Notes

Reaction equation

HRID 2354040 reaction equation
[CH3:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]([C:8]([NH2:10])=O)[CH:3]=1.[C:11]1(N)[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=1[NH2:17]>O>[CH3:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]([C:8]2[NH:10][C:11]3[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=3[N:17]=2)[CH:3]=1

Participants

4

Reactant 2

HCID 7243O-PhenylenediamineHCID 114992244-methylpyridine-2-carboxamide

Product 1

HCID 6394321H-benzimidazole, 2-(4-methyl-2-pyridinyl)-Yield 85%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
210 °C

Procedure

450 g of polyphosphoric acid, 40 g (0.29 mol) of 4-methyl-pyridine-2-carboxylic acid amide and 31 g (0.29 mol) of o-phenylendiamine are added in a three-neck round-bottom flask, equipped with a condenser, a thermometer and mechanical stirring. The mixture is heated at 210° C. for 4 hours. At the end, the mixture is cooled at 70° C. and the crude is added to 1 L of water. Basify with a 50% aqueous solution of sodium hydroxide and filter the solid obtained. Crystallize from absolute ethanol. The product 2-(4-methylpyridin-2-yl)-1H-benzoimidazol is obtained with a yield of 85%. Melting point: 228-9° C.

Workup

  1. customequipped with a condenser
  2. temperatureAt the end, the mixture is cooled at 70° C.
  3. filtrationBasify with a 50% aqueous solution of sodium hydroxide and filter the solid
  4. customobtained
  5. customCrystallize from absolute ethanol

Sources & evidence

ORD record
ord-e10955b879c94a98b461a64d008db2cf
Source dataset
uspto-grants-2010_07
Patent number
US07750157B2

Reaction notes

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