5-chloro-6-(piperidin-1-yl)-benzofuran-3(2H)-one → 5-Chloro-6-(piperidin-1-yl)-benzofuran

HRID 637679Notes

Reaction equation

HRID 637679 reaction equation
[Cl:1][C:2]1[C:3]([N:12]2[CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]2)=[CH:4][C:5]2[O:9][CH2:8][C:7](=O)[C:6]=2[CH:11]=1>C(OC(=O)C)(=O)C.C(O)(=O)C.CO.[Pt]=O>[Cl:1][C:2]1[C:3]([N:12]2[CH2:17][CH2:16][CH2:15][CH2:14][CH2:13]2)=[CH:4][C:5]2[O:9][CH:8]=[CH:7][C:6]=2[CH:11]=1

Participants

6

Reactant 1

HCID 202556645-chloro-6-(piperidin-1-yl)-benzofuran-3(2H)-one

Product 1

HCID 202556395-Chloro-6-(piperidin-1-yl)-benzofuran

Reagents, catalysts & solvents 4

HCID 82844Platinum oxide (PtO)CatalystHCID 176Acetic AcidSolventHCID 887MethanolSolventHCID 7918Acetic AnhydrideSolvent

Procedure

A solution of 2.51 g (10.0 mmole) of 5-chloro-6-(piperidin-1-yl)-benzofuran-3(2H)-one in 15 ml of acetic anhydride and 15 ml of glacial acetic acid is maintained at 100° for 24 hours. The reaction mixture is subsequently poured onto ice and extracted with methylene chloride. The organic phases are washed with water, combined, dried over sodium sulphate and concentrated in a vacuum rotary evaporator. The crude 3-acetoxy-5-chloro-6-(piperidin-1-yl)-benzofuran so obtained is dissolved in 15 ml of absolute methanol, 250 mg of platinum oxide are added and the whole is hydrogenated at 3 atmospheres and room temperature. The catalyst is filtered off and the filtrate is concentrated in a vacuum rotary evaporator. The residue is chromatographed over silica gel using methylene chloride as eluant (Rf =0.63). In that manner, 5-chloro-6-(piperidin-1-yl)-benzofuran is obtained in the form of an oil which distills at 96°-97°/1.5 torr.

Workup

  1. additionThe reaction mixture is subsequently poured onto ice
  2. extractionextracted with methylene chloride
  3. washThe organic phases are washed with water
  4. dry with materialdried over sodium sulphate
  5. concentrationconcentrated in a vacuum rotary evaporator
  6. customThe crude 3-acetoxy-5-chloro-6-(piperidin-1-yl)-benzofuran so obtained
  7. customis hydrogenated at 3 atmospheres and room temperature
  8. filtrationThe catalyst is filtered off
  9. concentrationthe filtrate is concentrated in a vacuum rotary evaporator
  10. customThe residue is chromatographed over silica gel

Sources & evidence

ORD record
ord-e26a39206cfb49ba992d1be41a8828b6
Source dataset
uspto-grants-1985_12
Patent number
US04558043

Reaction notes

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