4-Fluorobenzoic Acid → 2-(4-Fluorophenyl)-5-aminoimidazo[4,5-b]pyridine

HRID 396374

Reaction equation

HRID 396374 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[C:4]([NH2:9])[N:3]=1.[F:10][C:11]1[CH:19]=[CH:18][C:14]([C:15](O)=O)=[CH:13][CH:12]=1>>[F:10][C:11]1[CH:19]=[CH:18][C:14]([C:15]2[NH:8][C:7]3[C:2]([N:1]=2)=[N:3][C:4]([NH2:9])=[CH:5][CH:6]=3)=[CH:13][CH:12]=1

Participants

3

Reactant 2

HCID 99734-Fluorobenzoic AcidHCID 780152,3,6-Triaminopyridine

Product 1

HCID 224861322-(4-Fluorophenyl)-5-aminoimidazo[4,5-b]pyridine

Procedure

2,3,6-Triaminopyridine (Austin Products; 372 mg 3 mmol) and 4-fluorobenzoic acid (420 mg 3 mmol) are treated with polyphosphoric acid (30 g) at 150° C. for 1 h. The reaction mixture is poured on ice-water/NH3conc. and extracted with ethyl acetate three times. The combined organic phases are dried over Na2SO4, filtered and evaporated to dryness to yield the crude product, which is purified by SiO2 chromatography (acetone/cyclohexane 20/80 to 50/80) and rendered the title compound as pale yellow crystals (200 mg 29%)

Workup

  1. additionThe reaction mixture is poured on ice-water/NH3conc
  2. extractionand extracted with ethyl acetate three times
  3. dry with materialThe combined organic phases are dried over Na2SO4
  4. filtrationfiltered
  5. customevaporated to dryness

Sources & evidence

ORD record
ord-3f6790251a1d4b0389cd894f9ca98db6
Source dataset
uspto-grants-2003_08
Patent number
US06608072B1

Linked notes

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