Potassium Carbonate → tert-Butyl 4-(2-fluoroethyl)piperazine-1-carboxylate

Temperatur

85 °C

In a sealed tube, 1,1-dimethylethyl 1-piperazinecarboxylate (10.0 g, 54.0 mmol) was dissolved in 100 mL of THF. K2CO3 (11.2 g, 81.0 mmol) and 1-fluoro-2-iodoethane (11.3 g, 64.8 mmol) were added and the reaction was heated to 85° C. for 16 h. The reaction was cooled to rt and solids were filtered and washed with DCM. The filtrate was concentrated in vacuo being careful not to heat the H2O bath past 30° C. The resulting crude product, 1,1-dimethylethyl 4-(2-fluoroethyl)-1-piperazinecarboxylate was carried on to the next step without further purification. 1H NMR (400 MHz, DMSO-d6) δ ppm 4.48 (dt, JHF=47.8 Hz, J=4.9 Hz, 2H), 3.24-3.28 (m, 4H), 2.57 (dt, JHF=28.7, J=4.9 Hz, 2H), 2.31-2.36 (m, 4H), 1.34 (s, 9H).

1. temperatureThe reaction was cooled to rt
2. filtrationsolids were filtered
3. washwashed with DCM
4. concentrationThe filtrate was concentrated in vacuo
5. temperatureto heat the H2O bath past 30° C
6. customThe resulting crude product, 1,1-dimethylethyl 4-(2-fluoroethyl)-1-piperazinecarboxylate was carried on to the next step without further purification

ORD-Eintrag

ord-4902982dbb5f477aad256244277cc050

Quelldatensatz

uspto-grants-2012_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08093239B2