Potassium Carbonate → 1-(2-Fluoroethyl)piperazine
Reaction equation
[F:1][CH2:2][CH2:3][N:4]1[CH2:9][CH2:8][N:7](C(OC(C)(C)C)=O)[CH2:6][CH2:5]1.C([O-])([O-])=O.[K+].[K+]>CO.Cl>[F:1][CH2:2][CH2:3][N:4]1[CH2:9][CH2:8][NH:7][CH2:6][CH2:5]1Participants
5
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Conditions
- Temperature
- 30 °C
Procedure
Crude 1,1-dimethylethyl 4-(2-fluoroethyl)-1-piperazinecarboxylate was dissolved in 40 mL of MeOH and 40 mL 37% HCl. Reaction was stirred for 1 h. Carefully neutralized with solid K2CO3 and concentrated in vacuo being careful not to heat the H2O bath past 30° C. The resulting residue was taken up in diethyl ether and the solids were filtered and washed with diethyl ether and DCM several times. Filtrate was concentrated in vacuo, again being careful not to heat the H2O bath past 30° C., to give desired product 1-(2-fluoroethyl)piperazine (5.2 g, 73% over 2 steps) which was used without further purification. 1H NMR (400 MHz, DMSO-d6) δ ppm 4.40-4.57 (m, 2H), 2.64-2.73 (m, 4H), 2.53-2.61 (m, 1H), 2.46-2.53 (m, 2H), 2.29-2.40 (m, 4H).
Workup
- customReaction
- concentrationconcentrated in vacuo
- filtrationthe solids were filtered
- washwashed with diethyl ether and DCM several times
- concentrationFiltrate was concentrated in vacuo
- temperatureto heat the H2O bath past 30° C.
Sources & evidence
- ORD record
- ord-27f32d5de6d9494ca496bf1e5e65e7b7
- Source dataset
- uspto-grants-2012_01
- Patent number
- US08093239B2
Reaction notes
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