Acetic Anhydride → 3-Chloro-6,7-dihydro-5H-cyclopenta[b]pyridin-7-yl Acetate

HRID 403255Notes

Reaction equation

HRID 403255 reaction equation
[Cl:1][C:2]1[CH:3]=[N+:4]([O-])[C:5]2[CH2:6][CH2:7][CH2:8][C:9]=2[CH:10]=1.[C:12]([O:15]C(=O)C)(=[O:14])[CH3:13]>>[Cl:1][C:2]1[CH:3]=[N:4][C:5]2[CH:6]([O:15][C:12](=[O:14])[CH3:13])[CH2:7][CH2:8][C:9]=2[CH:10]=1

Participants

3

Reactant 2

HCID 7918Acetic AnhydrideHCID 580828393-Chloro-6,7-dihydro-5h-cyclopenta[b]pyridine 1-oxide

Product 1

HCID 580827683-Chloro-6,7-dihydro-5H-cyclopenta[b]pyridin-7-yl Acetate

Procedure

A solution of 3-chloro-6,7-dihydro-5H-[1]pyrindine 1-oxide (2.07 g, 12.2 mmol) in acetic acid anhydride (62.2 ml, 659 mmol) was stirred at 110° C. for 20 hours. For the workup, the solvent was removed at reduced pressure and the residue quenched with saturated aqueous solution of sodium hydrogen carbonate. The aqueous phase was extracted with dichloromethane, the resulting organic layers combined and dried over sodium sulfate. After evaporation of the solvent, the residue was purified by flash chromatography on silica gel using a gradient of heptane/ethyl acetate=100:0 to 70:30 as the eluent. The acetic acid 3-chloro-6,7-dihydro-5H-[1]pyrindin-7-yl ester was obtained as a red liquid (1.57 g, 61%); (calculated) C10H10ClNO2 [211.65]; (found) [M+H]+=212.

Workup

  1. customFor the workup, the solvent was removed at reduced pressure
  2. customthe residue quenched with saturated aqueous solution of sodium hydrogen carbonate
  3. extractionThe aqueous phase was extracted with dichloromethane
  4. dry with materialdried over sodium sulfate
  5. customAfter evaporation of the solvent
  6. customthe residue was purified by flash chromatography on silica gel using a gradient of heptane/ethyl acetate=100:0 to 70:30 as the eluent

Sources & evidence

ORD record
ord-70a89fe382ab49d6a575d15fe3adb4be
Source dataset
uspto-grants-2014_06
Patent number
US08748418B2

Reaction notes

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