Potassium Carbonate → 1-Boc-4-(2-formylphenyl)piperazine

HRID 228116Notes

Reaction equation

F[C:2]1[CH:9]=[CH:8][CH:7]=[CH:6][C:3]=1[CH:4]=[O:5].[C:10]([N:17]1[CH2:22][CH2:21][NH:20][CH2:19][CH2:18]1)([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11].C([O-])([O-])=O.[K+].[K+]>CN(C=O)C.[Cu]>[CH:4]([C:3]1[CH:6]=[CH:7][CH:8]=[CH:9][C:2]=1[N:20]1[CH2:19][CH2:18][N:17]([C:10]([O:12][C:13]([CH3:16])([CH3:15])[CH3:14])=[O:11])[CH2:22][CH2:21]1)=[O:5]

Participants

Conditions

Temperature: 150 °C

Procedure

To a solution of 2-fluorobenzaldehyde (Aldrich) (1 g, 8.1 mmol) in DMF (14 mL) was added 1-Boc-piperazine (Lancaster) (2.3 g, 12 mmol). The resulting solution was treated with copper (Aldrich Chemical Company) (50 mg, 0.8 mmol) and K2CO3 (Aldrich) (5.1 g, 37 mmol). The suspension was heated in a sealed tube at 150° C. for 18 h. After cooling to RT, the reaction mixture was partitioned between EtOAc and brine. The aqueous layer was extracted twice with EtOAc and the combined EtOAc layers were washed with water, dried over Na2SO4, filtered and concentrated in vacuo. The crude compound was purified on a Biotage 40 M column (12% EtOAc in hexanes) to give tert-butyl 4-(2-formylphenyl)piperazinecarboxylate (0.66 g) as a yellow oil. MS m/z: 291 (M+H). Calc'd for C16H22N2O3: 290.36.

Workup

temperatureAfter cooling to RT
customthe reaction mixture was partitioned between EtOAc and brine
extractionThe aqueous layer was extracted twice with EtOAc
washthe combined EtOAc layers were washed with water
dry with materialdried over Na2SO4
filtrationfiltered
concentrationconcentrated in vacuo
customThe crude compound was purified on a Biotage 40 M column (12% EtOAc in hexanes)

Sources & evidence

ORD record: ord-e4d3cdc4d708415fb5ea57c991e18aa7
Source dataset: uspto-grants-2009_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07560460B2

Reaction notes

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