Ethylene Glycol → tert-butyl 4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazine-1-carboxylate

HRID 1890812Notes

Reaction equation

HRID 1890812 reaction equation
[O:1]=[C:2]1[NH:7][CH2:6][CH2:5][N:4]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:3]1.[CH3:15][N:16]1[CH:20]=[C:19](I)[CH:18]=[N:17]1.C(O)CO.P([O-])([O-])([O-])=O.[K+].[K+].[K+]>C(O)(C)C.[Cu](I)I>[CH3:15][N:16]1[CH:20]=[C:19]([N:7]2[CH2:6][CH2:5][N:4]([C:8]([O:10][C:11]([CH3:14])([CH3:13])[CH3:12])=[O:9])[CH2:3][C:2]2=[O:1])[CH:18]=[N:17]1

Participants

7

Reactant 4

HCID 174Ethylene GlycolHCID 62657Potassium Phosphate, TribasicHCID 27347731-Methyl-4-iodo-1H-pyrazoleHCID 3157178Tert-butyl 3-oxopiperazine-1-carboxylate

Product 1

HCID 67153719tert-butyl 4-(1-methyl-1H-pyrazol-4-yl)-3-oxopiperazine-1-carboxylate

Reagents, catalysts & solvents 2

HCID 83717Copper iodideCatalystHCID 3776IsopropanolSolvent

Procedure

tert-Butyl 3-oxopiperazine-1-carboxylate (0.164 g, 0.819 mmol) was suspended in isopropanol (3 mL) under an atmosphere of nitrogen and treated with 1-methyl-4-iodo-1H-pyrazole (0.204 g, 0.983 mmol, 1.20 equiv), ethylene glycol (0.051 g, 0.82 mmol, 1.0 equiv), copper iodide (0.031 g, 0.16 mmol, 0.20 equiv), and potassium phosphate (0.695 g, 3.28 mmol, 4.00 equiv), and placed into a preheated oil bath at 100° C. for 8 hours. The mixture was cooled to ambient temperature, concentrated in vacuo and the residue was dissolved in dichloromethane, washed with water, dried with sodium sulfate, filtered, and concentrated in vacuo. The residue was purified by silica gel chromatography (100:0 to 0:100 hexanes:ethyl acetate), providing the titled compound.

Workup

  1. concentrationconcentrated in vacuo
  2. dissolutionthe residue was dissolved in dichloromethane
  3. washwashed with water
  4. dry with materialdried with sodium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated in vacuo
  7. customThe residue was purified by silica gel chromatography (100:0 to 0:100 hexanes:ethyl acetate)

Sources & evidence

ORD record
ord-fafb75c317704ee8b599046f05fc0984
Source dataset
uspto-grants-2013_08
Patent number
US08507494B2

Reaction notes

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