Citric Acid → 4-[2-(5-Bromo-2-chloropyridin-4-yl)-1-hydroxy-ethyl]piperidine-1-carboxylic acid tert-butyl ester

HRID 872197Notes

Reaction equation

HRID 872197 reaction equation
[BH4-].[Na+].[C:3]([O:7][C:8]([N:10]1[CH2:15][CH2:14][CH:13]([C:16](=[O:26])[CH2:17][C:18]2[C:23]([Br:24])=[CH:22][N:21]=[C:20]([Cl:25])[CH:19]=2)[CH2:12][CH2:11]1)=[O:9])([CH3:6])([CH3:5])[CH3:4].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>O1CCCC1.O>[C:3]([O:7][C:8]([N:10]1[CH2:11][CH2:12][CH:13]([CH:16]([OH:26])[CH2:17][C:18]2[C:23]([Br:24])=[CH:22][N:21]=[C:20]([Cl:25])[CH:19]=2)[CH2:14][CH2:15]1)=[O:9])([CH3:6])([CH3:4])[CH3:5]

Participants

6

Reactant 3

HCID 311Citric AcidHCID 4311764Sodium borohydrideHCID 866748944-[2-(5-Bromo-2-chloropyridin-4-yl)acetyl]piperidine-1-carboxylic acid tert-butyl ester

Product 1

HCID 866748964-[2-(5-Bromo-2-chloropyridin-4-yl)-1-hydroxy-ethyl]piperidine-1-carboxylic acid tert-butyl ester

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent

Procedure

Sodium borohydride (0.24 g) is added to an ice-cold solution of 4-[2-(5-bromo-2-chloro-pyridin-4-yl)-acetyl]-piperidine-1-carboxylic acid tert-butyl ester (1.65 g) in tetrahydrofuran (40 mL) and water (10 mL). The resulting mixture is stirred for 0.5 h. 2 N aqueous citric acid solution is added and the mixture is extracted with ethyl acetate. The combined extracts are washed with aqueous NaHCO3 solution and brine, dried (MgSO4), and concentrated. The residue is chromatographed on silica gel (cyclohexane/ethyl acetate 65:35) to give the title compound. Mass spectrum (ESI+): m/z=419/421/423 (Cl+Br) [M+H]+.

Workup

  1. extractionthe mixture is extracted with ethyl acetate
  2. washThe combined extracts are washed with aqueous NaHCO3 solution and brine
  3. dry with materialdried (MgSO4)
  4. concentrationconcentrated
  5. customThe residue is chromatographed on silica gel (cyclohexane/ethyl acetate 65:35)

Sources & evidence

ORD record
ord-7490d6b2c5d6456caffdc5b1404a9dff
Source dataset
uspto-grants-2015_03
Patent number
US08975277B2

Reaction notes

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