Potassium Carbonate → t-Butyl 4-carboethoxypropyl-1-piperazinecaboxylate

HRID 1601446Notes

Reaction equation

HRID 1601446 reaction equation
[N:1]1([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:6][CH2:5][NH:4][CH2:3][CH2:2]1.Cl[CH2:15][CH2:16][CH2:17][C:18]([O:20][CH2:21][CH3:22])=[O:19].C(=O)([O-])[O-].[K+].[K+].C(OCC)(=O)C.CCCCCC>CN(C)C=O.C(=O)(O)[O-].[Na+]>[C:18]([CH2:17][CH2:16][CH2:15][N:4]1[CH2:5][CH2:6][N:1]([C:7]([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8])[CH2:2][CH2:3]1)([O:20][CH2:21][CH3:22])=[O:19]

Participants

7

Reactant 4

HCID 11430Potassium CarbonateHCID 18474Ethyl 4-chlorobutyrateHCID 143452tert-Butyl piperazine-1-carboxylateHCID 21226206Ethyl acetate hexane3×

Product 1

HCID 54157782t-Butyl 4-carboethoxypropyl-1-piperazinecaboxylate

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 516892Sodium BicarbonateSolvent

Procedure

Combine t-butyl 1-piperazinecarboxylate (10.7 g, 57.5 mmol), ethyl 4-chlorobutyrate (10.4 mL), and potassium carbonate (8 g) in dimethylformamide (60 mL). Heat at reflux. After 4.5, hours, cool the reaction, dilute with an aqueous solution of sodium bicarbonate, and extract twice with diethyl ether (200 mL). Combine the organic layers and extract with a 1M aqueous solution of hydrochloric acid. Adjust the pH of the aqueous layer to basic using sodium bicarbonate and then extract twice with diethyl ether. Dry the combined organic layers over MgSO4, filter, and evaporate in vacuo to give a residue. Chromatograph the residue on silica gel eluting sequentially with 10% ethyl acetate/hexane, 20% ethyl acetate/hexane, 25% ethyl acetate/hexane to give t-butyl 4-carboethoxypropyl-1-piperazinecarboxylate. Rf =0.5 (silica gel, ethyl acetate).

Workup

  1. temperatureHeat
  2. temperatureat reflux
  3. temperatureAfter 4.5, hours, cool
  4. customthe reaction
  5. extractionextract twice with diethyl ether (200 mL)
  6. extractionCombine the organic layers and extract with a 1M aqueous solution of hydrochloric acid
  7. extractionextract twice with diethyl ether
  8. dry with materialDry the combined organic layers over MgSO4
  9. filtrationfilter
  10. customevaporate in vacuo
  11. customto give a residue

Sources & evidence

ORD record
ord-f73b5f87f9af431b9416fb9262ad3814
Source dataset
uspto-grants-1999_11
Patent number
US05977139

Reaction notes

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