Ethylene Glycol → Tert-butyl 4-(5-bromopyridin-3-yl)piperazine-1-carboxylate

HRID 270549Notes

Reaction equation

HRID 270549 reaction equation
[Br:1][C:2]1[CH:3]=[N:4][CH:5]=[C:6](I)[CH:7]=1.[N:9]1([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:14][CH2:13][NH:12][CH2:11][CH2:10]1.[O-]P([O-])([O-])=O.[K+].[K+].[K+].C(O)CO>C(O)(C)C.[Cu]I>[Br:1][C:2]1[CH:7]=[C:6]([N:12]2[CH2:11][CH2:10][N:9]([C:15]([O:17][C:18]([CH3:21])([CH3:20])[CH3:19])=[O:16])[CH2:14][CH2:13]2)[CH:5]=[N:4][CH:3]=1

Participants

7

Reactant 4

HCID 174Ethylene GlycolHCID 62657Potassium Phosphate, TribasicHCID 143452tert-Butyl piperazine-1-carboxylateHCID 8204093-Bromo-5-iodopyridine

Product 1

HCID 11653049Tert-butyl 4-(5-bromopyridin-3-yl)piperazine-1-carboxylateYield 37%

Reagents, catalysts & solvents 2

HCID 24350Copper(1+) iodide; Copper(I) iodide; Cuprous iodide; Cuprous iodide (CuI)CatalystHCID 3776IsopropanolSolvent

Procedure

A solution of 3-bromo-5-iodopyridine (13.0 g, 45.8 mmol), tert-butyl piperazine-1-carboxylate (8.53 g, 45.8 mmol), copper(I) iodide (0.871 g, 4.57 mmol), K3PO4 (19.46 g, 91.68 mmol), 1,2-ethanediol (5.1 mL, 91 mmol) in isopropyl alcohol (80 mL) in a sealed tube was heated at 80° C. in an oil bath for 2 days. After cooling to room temperature, the reaction mixture was filtered through celite. The filtrate was concentrated in vacuo. The residue was taken up in EtOAc and the solution was washed with saturated NaHCO3, dried (MgSO4) and concentrated. Purification by flash chromatography on silica gel (20% EtOAc/hexanes to 30% EtOAc/hexanes) afforded 5.75 g (37%) of desired product. MS calculated for C14H20BrN3O2: (M+H) 343; found 342.0, 344.0.

Workup

  1. filtrationthe reaction mixture was filtered through celite
  2. concentrationThe filtrate was concentrated in vacuo
  3. washthe solution was washed with saturated NaHCO3
  4. dry with materialdried (MgSO4)
  5. concentrationconcentrated
  6. customPurification by flash chromatography on silica gel (20% EtOAc/hexanes to 30% EtOAc/hexanes)

Sources & evidence

ORD record
ord-46851af5ea2349b59a86c999536d7db4
Source dataset
uspto-grants-2008_11
Patent number
US07449467B2

Reaction notes

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