O-Phenylenediamine → 6-(1H-benzo[d]imidazol-2-yl)pyridin-2-amine

HRID 416652

Reaction equation

HRID 416652 reaction equation
[NH2:1][C:2]1[N:7]=[C:6]([C:8](O)=O)[CH:5]=[CH:4][CH:3]=1.NC1C=C(C(O)=O)C=CN=1.NC1C=C(C(O)=O)C=NC=1.[NH2:31][C:32]1[CH:37]=[CH:36][CH:35]=[CH:34][C:33]=1[NH2:38].[OH-].[Na+]>>[NH:31]1[C:32]2[CH:37]=[CH:36][CH:35]=[CH:34][C:33]=2[N:38]=[C:8]1[C:6]1[N:7]=[C:2]([NH2:1])[CH:3]=[CH:4][CH:5]=1

Participants

6

Reactant 5

HCID 7243O-PhenylenediamineHCID 14798Sodium HydroxideHCID 2783962-Aminopyridine-4-carboxylic acidHCID 3516526-Aminopyridine-2-carboxylic acidHCID 3543165-Aminonicotinic Acid

Product 1

HCID 596798656-(1H-benzo[d]imidazol-2-yl)pyridin-2-amineYield 61.6%

Procedure

A suspension of 6-aminopyridine-2-carboxylic acid (112 mg), or 2-aminopyridine-4-carboxylic acid (112 mg, 0.82 mmol), or 5-aminopyridine-3-carboxylic acid (112 mg, 0.82 mmol) with 1,2-diaminobenzene (177 mg, 1.64 mmol) was heated in 4 mL of PPA (180 degree) for 2 h. The reaction mixture was each poured into 50 mL ice-water and neutralized with 2 N NaOH (chilled) during vigorous stirring. The resulting precipitate was filtered and washed with 20 mL warm water to afford 105 mg of desired 6-(1H-benzo[d]imidazol-2-yl)pyridin-2-amine (MS, M++H=211.1).

Workup

  1. temperaturewas heated in 4 mL of PPA (180 degree) for 2 h
  2. filtrationThe resulting precipitate was filtered
  3. washwashed with 20 mL
  4. temperaturewarm water

Sources & evidence

ORD record
ord-1af375157da243288daf219d966cdbe2
Source dataset
uspto-grants-2012_01
Patent number
US08088928B2

Linked notes

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