Water → tert-Butyl 4-(thiazol-2-yl)piperazine-1-carboxylate

HRID 1243331Notes

Reaction equation

HRID 1243331 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.Br[C:15]1[S:16][CH:17]=[CH:18][N:19]=1.C([O-])([O-])=O.[K+].[K+].O>CCO>[S:16]1[CH:17]=[CH:18][N:19]=[C:15]1[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

Participants

6

Reactant 4

HCID 962WaterHCID 11430Potassium CarbonateHCID 764302-BromothiazoleHCID 143452tert-Butyl piperazine-1-carboxylate

Product 1

HCID 21925505tert-Butyl 4-(thiazol-2-yl)piperazine-1-carboxylateYield 69.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 5 g of tert-butyl 1-piperazinecarboxylate, 4.4 g of 2-bromo-1,3-thiazole and 7.4 g of K2CO3 in 50 ml of EtOH is refluxed for 4 days. Water is added to the reaction mixture, the EtOH is evaporated off under vacuum, the resulting aqueous phase is extracted with EtOAc, the organic phase is washed with saturated K2CO3 solution and with saturated NaCl solution and dried over Na2SO4, and the solvent is evaporated off under vacuum. The residue is chromatographed on silica gel, eluting with a DCM/MeOH mixture (98/2; v/v). 5 g of the expected product are obtained after precipitation from a cold DCM/hexane mixture and filtration by suction, m.p.=114–116° C.

Workup

  1. temperatureis refluxed for 4 days
  2. customthe EtOH is evaporated off under vacuum
  3. extractionthe resulting aqueous phase is extracted with EtOAc
  4. washthe organic phase is washed with saturated K2CO3 solution and with saturated NaCl solution
  5. dry with materialdried over Na2SO4
  6. customthe solvent is evaporated off under vacuum
  7. customThe residue is chromatographed on silica gel
  8. washeluting with a DCM/MeOH mixture (98/2; v/v)

Sources & evidence

ORD record
ord-d15756a8e67a49bdacbbdba194227406
Source dataset
uspto-grants-2006_10
Patent number
US07119086B2

Reaction notes

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