Acetic Anhydride → 3-Nitro-7,8-dihydro-6H-pyrrolo[2',1':2,3]imidazo[4,5-b]pyridin-6-yl acetate

HRID 1691596Notes

Reaction equation

HRID 1691596 reaction equation
[N:1]1([C:6]2[C:11]([N+:12]([O-])=O)=[CH:10][C:9]([N+:15]([O-:17])=[O:16])=[CH:8][N:7]=2)[CH2:5][CH2:4][CH2:3][CH2:2]1.[C:18]([O:21]C(=O)C)(=[O:20])[CH3:19]>[Cl-].[Zn+2].[Cl-]>[C:18]([O:21][CH:4]1[C:5]2=[N:12][C:11]3[C:6](=[N:7][CH:8]=[C:9]([N+:15]([O-:17])=[O:16])[CH:10]=3)[N:1]2[CH2:2][CH2:3]1)(=[O:20])[CH3:19]

Participants

4

Reactant 2

HCID 7918Acetic AnhydrideHCID 230642833,5-Dinitro-2-pyrrolidin-1-ylpyridine

Product 1

HCID 669051873-Nitro-7,8-dihydro-6H-pyrrolo[2',1':2,3]imidazo[4,5-b]pyridin-6-yl acetate

Reagents, catalysts & solvents 1

HCID 3007855ZincchlorideCatalyst2×

Procedure

A mixture of 1 g (4.2 mmol) of 2-(pyrrolidin-1-yl)-3,5-dinitropyridine (Org. & Biomol. Chem. 2003, 1(6), 1004-1011) and 0.584 g (4.2 mmol) of zinc chloride in 10 ml of acetic anhydride is heated at reflux for six hours. After this time a further 0.584 g (4.2 mmol) of zinc chloride are added and the stirring at reflux is maintained for eighteen hours. After this time the mixture is poured onto 100 g of ice and then extracted with three times 50 ml of ethyl acetate. The organic phases are combined and then washed with twice 20 ml of saturated sodium hydrogen carbonate solution, once with 20 ml of water and then once with 50 ml of saturated sodium chloride solution, then dried over sodium sulfate and concentrated under reduced pressure. The product obtained is purified by chromatography on a silica column, eluting with a mixture of ethyl acetate and n-heptane. The resulting product is recrystallized from a mixture of diisopropyl ether and isopropanol. This gives 0.29 g of the expected compound.

Workup

  1. temperatureis heated
  2. temperatureat reflux for six hours
  3. temperaturethe stirring at reflux
  4. temperatureis maintained for eighteen hours
  5. extractionextracted with three times 50 ml of ethyl acetate
  6. washwashed with twice 20 ml of saturated sodium hydrogen carbonate solution, once with 20 ml of water
  7. dry with materialonce with 50 ml of saturated sodium chloride solution, then dried over sodium sulfate
  8. concentrationconcentrated under reduced pressure
  9. customThe product obtained
  10. customis purified by chromatography on a silica column
  11. washeluting with a mixture of ethyl acetate and n-heptane
  12. customThe resulting product is recrystallized from a mixture of diisopropyl ether and isopropanol

Sources & evidence

ORD record
ord-7e55fabf61c54a9296ba2917402b8638
Source dataset
uspto-grants-2012_04
Patent number
US08153796B2

Reaction notes

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