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

HRID 1886174Notes

Reaction equation

HRID 1886174 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-8be12386abcb4db7bf0ab08537399129
Source dataset
uspto-grants-1992_09
Patent number
US05149814

Reaction notes

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