Potassium Carbonate → HCID 67666471, compound

HRID 1459410Notes

Reaction equation

HRID 1459410 reaction equation
[C:1]([NH:4][C:5]1[CH:10]=[CH:9][C:8]([CH2:11][CH2:12]Br)=[CH:7][CH:6]=1)(=[O:3])[CH3:2].[C:14]([O:18][C:19]([N:21]1[CH2:26][CH2:25][NH:24][CH2:23][CH2:22]1)=[O:20])([CH3:17])([CH3:16])[CH3:15].C([O-])([O-])=O.[K+].[K+]>CC(O)C>[C:14]([O:18][C:19]([N:21]1[CH2:26][CH2:25][N:24]([CH2:12][CH2:11][C:8]2[CH:9]=[CH:10][C:5]([NH:4][C:1](=[O:3])[CH3:2])=[CH:6][CH:7]=2)[CH2:23][CH2:22]1)=[O:20])([CH3:17])([CH3:15])[CH3:16]

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 143452tert-Butyl piperazine-1-carboxylateHCID 18690059HCID 18690059, compound

Product 1

HCID 67666471HCID 67666471, compoundYield 49%

Reagents, catalysts & solvents 1

HCID 3776IsopropanolSolvent

Conditions

Temperature
100 °C

Procedure

2-[4-(Acetylamino)phenyl]ethyl bromide (2.6 g, 10.7 mmol) was added to a mixture of N-tert-butyloxycarbonyl piperazine (2.0 g, 10.7 mmol) and K2CO3 (3.0 g, 21.7 mmol), in IPA (100 ml), and heated at 100° C. for 16 h. The mixture was filtered and the filtrate evaporated under vacuum. The residue was taken up into ethyl acetate and washed with H2O . The aqueous phase was extracted with EtOAc and the combined extracts dried (Na2SO4 /MgSO4) and evaporated. The crude product was chromatographed on silica gel eluting with ethyl acetate to give 1-tert-butyloxycarbonyl-4-[2-(4-(acetylamino)phenyl)ethyl]piperazine (1.8 g, 49%) which was shown to be pure by 1H NMR. A solution of the preceding N-Boc piperazine (1.8 g, 5.19 mmol) in 99% formic acid (30 ml) was stirred at room temperature for 16 h. The solvent was removed under vacuum and the product chromatographed on silica gel eluting with CH2Cl2 / MeOH/NH3 (50:8:1) to give the title-piperazine (1.3 g, 100%) δ(250 MHz, D6 -DMSO) 2.01 (3H, s, Me), 2.26-2.72 (12H, m, 6 of CH2), 7.12 (2H, d, J=8.5 Hz, Ar-H), 7.46 (2H, d, J=8.5 Hz, Ar-H), 9.85 (1H, s, NH).

Workup

  1. filtrationThe mixture was filtered
  2. customthe filtrate evaporated under vacuum
  3. washwashed with H2O
  4. extractionThe aqueous phase was extracted with EtOAc
  5. dry with materialthe combined extracts dried (Na2SO4 /MgSO4)
  6. customevaporated
  7. customThe crude product was chromatographed on silica gel eluting with ethyl acetate

Sources & evidence

ORD record
ord-b8be03702f004653994ee2e51ed52af1
Source dataset
uspto-grants-1998_12
Patent number
US05854247

Reaction notes

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