4-Fluorobenzoic Acid → 5Chloro-2-(4fluorophenyl)imidazo[4,5-b]pyridine

HRID 2181412Notes

Reaction equation

HRID 2181412 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[C:4]([Cl:9])[N:3]=1.[F:10][C:11]1[CH:19]=[CH:18][C:14]([C:15](O)=O)=[CH:13][CH:12]=1>>[Cl:9][C:4]1[N:3]=[C:2]2[N:1]=[C:15]([C:14]3[CH:18]=[CH:19][C:11]([F:10])=[CH:12][CH:13]=3)[NH:8][C:7]2=[CH:6][CH:5]=1

Participants

3

Reactant 2

HCID 99734-Fluorobenzoic AcidHCID 106306156-Chloropyridine-2,3-diamine

Product 1

HCID 224861255Chloro-2-(4fluorophenyl)imidazo[4,5-b]pyridineYield 46.6%

Procedure

2,3-Diamino-6-chloropyridine (Davos-Bulk supplier, 2.25 g 15.6 mmol) and 4-fluorobenzoic acid (2.62 g 18.7 mmol) are treated with polyphosphoric acid (56.4 g) at 150° C. for 6 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 recrystallisation from ethyl acetate/tert.butyl methyl ether to yield the title compound (1.8 g 44%) as grey crystals.

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
  6. customto yield the crude product, which
  7. customis purified by recrystallisation from ethyl acetate/tert.butyl methyl ether

Sources & evidence

ORD record
ord-7cfe165ef46c4f2491e309f480ca4505
Source dataset
uspto-grants-2005_05
Patent number
US06891039B2

Reaction notes

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