Hydrochloric Acid → 2-(Fluoromethyl)piperazine dihydrochloride

A mixture of a solution of 23.85 g (0.08 mole) of 1,4-dibenzyl-2-fluoromethylpiperazine [prepared as described in step (c) above] in 500 ml of methanol and 33 ml of concentrated aqueous hydrochloric acid was stirred vigorously at room temperature for 1 hour in an atmosphere of hydrogen and in the presence of 1.0 g of 20% w/w palladium-on-carbon. At the end of this time, the catalyst was removed by filtration and washed with water. The filtrate and washings were concentrated by evaporation under reduced pressure, and the residue was dissolved in 200 ml of water. The resulting aqueous solution was washed vigorously with ethyl acetate and separated. The aqueous layer was concentrated by evaporation under reduced pressure, and the residue was washed with ethanol to afford 13.76 g of 2-fluoromethylpiperazine dihydrochloride as a colorless powder, melting at 205°-218° C.

1. customAt the end of this time, the catalyst was removed by filtration
2. washwashed with water
3. concentrationThe filtrate and washings were concentrated by evaporation under reduced pressure
4. dissolutionthe residue was dissolved in 200 ml of water
5. washThe resulting aqueous solution was washed vigorously with ethyl acetate
6. customseparated
7. concentrationThe aqueous layer was concentrated by evaporation under reduced pressure
8. washthe residue was washed with ethanol

ORD record

ord-c221cfdebc9c4161b9bc59561ff48598

Source dataset

uspto-grants-1995_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05436367