Sodium Hydroxide → 1-[1-(3-tert-Butoxy-2-pyrazinylmethyl)piperidin-4-yl)-2-(2-chlorophenyl)ethanone

HRID 890079Notes

Reaction equation

HRID 890079 reaction equation
Cl.[Cl:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:9][C:10]([CH:12]1[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1)=[O:11].[C:18]([O:22][C:23]1[C:24]([CH:29]=O)=[N:25][CH:26]=[CH:27][N:28]=1)([CH3:21])([CH3:20])[CH3:19].C(O[BH-](OC(=O)C)OC(=O)C)(=O)C.[Na+].[OH-].[Na+]>ClCCl>[C:18]([O:22][C:23]1[C:24]([CH2:29][N:15]2[CH2:14][CH2:13][CH:12]([C:10](=[O:11])[CH2:9][C:4]3[CH:5]=[CH:6][CH:7]=[CH:8][C:3]=3[Cl:2])[CH2:17][CH2:16]2)=[N:25][CH:26]=[CH:27][N:28]=1)([CH3:21])([CH3:20])[CH3:19]

Participants

6

Reactant 4

HCID 14798Sodium HydroxideHCID 5049666Sodium triacetoxyborohydrideHCID 222482803-(tert-Butoxy)pyrazine-2-carbaldehydeHCID 222485334-(2-Chlorophenylacetyl)piperidine hydrochloride

Product 1

HCID 222482661-[1-(3-tert-Butoxy-2-pyrazinylmethyl)piperidin-4-yl)-2-(2-chlorophenyl)ethanoneYield 78%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

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. additionwere added
  2. extractionextraction
  3. washThe organic layer was washed with saturated brine
  4. dry with materialdried over anhydrous magnesium sulfate
  5. distillationthe solvent was distilled off under reduced pressure
  6. customThe residue was purified by silica gel column chromatography (solvent: n-hexane/ethyl acetate)

Sources & evidence

ORD record
ord-645220b95f9941acb534cd76b28e8756
Source dataset
uspto-grants-2006_02
Patent number
US06995144B2

Reaction notes

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