1-(1-Benzylpiperidin-4-yl)-2-(2-chlorophenyl)ethanone → 4-(2-Chlorophenylacetyl)piperidine hydrochloride

HRID 914866Notes

Reaction equation

HRID 914866 reaction equation
C([N:8]1[CH2:13][CH2:12][CH:11]([C:14](=[O:23])[CH2:15][C:16]2[CH:21]=[CH:20][CH:19]=[CH:18][C:17]=2[Cl:22])[CH2:10][CH2:9]1)C1C=CC=CC=1>ClCCCl.ClC(OC(Cl)C)=O>[ClH:22].[Cl:22][C:17]1[CH:18]=[CH:19][CH:20]=[CH:21][C:16]=1[CH2:15][C:14]([CH:11]1[CH2:10][CH2:9][NH:8][CH2:13][CH2:12]1)=[O:23]

Participants

4

Procedure

After dissolving 252 mg of 1-(1-benzylpiperidin-4-yl)-2-(2-chlorophenyl)ethanone in 3 ml of 1,2-dichloroethane, 0.1 ml of 1-chloroethyl chloroformate was added while stirring on ice, and the mixture was heated to reflux for 1 hour. The reaction solution was concentrated under reduced pressure, 3 ml of methanol was added to the residue, and heating to reflux was continued for 30 minutes. The reaction solution was concentrated under reduced pressure, ethyl acetate was added to the residue and the precipitate was filtered out to obtain 171 mg of 4-(2-chlorophenylacetyl)piperidine hydrochloride. After then suspending 98 mg of the 4-(2-chlorophenylacetyl)piperidine hydrochloride in 3 ml of dichloromethane, 77 mg of 3-tert-butoxypyrazine-2-carboxaldehyde and 114 mg of sodium triacetoxyborohydride were added while stirring on ice, and the stirring was continued overnight at room temperature. A 1N sodium hydroxide solution was added to the reaction mixture to render it alkaline, and then extraction was performed with ethyl acetate. The organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate, and then the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (solvent: n-hexane/ethyl acetate) to obtain the title compound (112 mg, 78% yield).

Workup

  1. additionwas added
  2. temperaturethe mixture was heated
  3. temperatureto reflux for 1 hour
  4. concentrationThe reaction solution was concentrated under reduced pressure, 3 ml of methanol
  5. additionwas added to the residue
  6. temperatureheating
  7. temperatureto reflux
  8. concentrationThe reaction solution was concentrated under reduced pressure, ethyl acetate
  9. additionwas added to the residue
  10. filtrationthe precipitate was filtered out

Sources & evidence

ORD record
ord-32c03495d1fc40d392fbf90caa1124b1
Source dataset
uspto-grants-2007_09
Patent number
US07265108B2

Reaction notes

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