Propionic anhydride → 1-(4-Cyanophenyl)-2-ethylimidazo[4,5-c]pyridine

HRID 973473Notes

Reaction equation

HRID 973473 reaction equation
[NH2:1][C:2]1[CH:3]=[N:4][CH:5]=[CH:6][C:7]=1[NH:8][C:9]1[CH:14]=[CH:13][C:12]([C:15]#[N:16])=[CH:11][CH:10]=1.[C:17](OC(=O)CC)(=O)[CH2:18][CH3:19].C(=O)(O)[O-].[Na+]>>[C:15]([C:12]1[CH:13]=[CH:14][C:9]([N:8]2[C:7]3[CH:6]=[CH:5][N:4]=[CH:3][C:2]=3[N:1]=[C:17]2[CH2:18][CH3:19])=[CH:10][CH:11]=1)#[N:16]

Participants

4

Reactant 3

HCID 31263Propionic anhydrideHCID 516892Sodium BicarbonateHCID 105364203-Amino-4-[N-(4-cyanophenyl)amino]pyridine

Product 1

HCID 150053971-(4-Cyanophenyl)-2-ethylimidazo[4,5-c]pyridineYield 22%

Procedure

A mixture of 3-amino-4-(4'-cyanophenyl)aminopyridine (Preparation 26(b)) (2.00 g, 9.5 mmol) and propionic anhydride (12.2 ml, 95 mmol) were heated together under nitrogen at reflux for 17 hours. The resulting solution was treated with excess aqueous sodium bicarbonate and the product was extracted into dichloromethane (3×150 ml). The combined extracts were dried (MgSO4), concentrated under reduced pressure, and the residue was purified by flash chromatography (gradient elution with ethyl acetate/methanol) to give the title compound as a brown solid (510 mg, 22%).

Workup

  1. temperaturewere heated together under nitrogen
  2. temperatureat reflux for 17 hours
  3. extractionthe product was extracted into dichloromethane (3×150 ml)
  4. dry with materialThe combined extracts were dried (MgSO4)
  5. concentrationconcentrated under reduced pressure
  6. customthe residue was purified by flash chromatography (gradient elution with ethyl acetate/methanol)

Sources & evidence

ORD record
ord-4079d4a438f443b59e1507179a61b824
Source dataset
uspto-grants-1991_11
Patent number
US05063237

Reaction notes

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