Reaction #78074

Reaction equation

1-acetylpiperazine

2-chloro-4′-fluoroacetophenone

potassium hydrogen carbonate

→

1-acetyl-4-(4-fluorophenylcarbonylmethyl)-piperazine hydrochloride

Yield 99.9%

Solvents

acetonitrile

Conditions

Workup

1. 1
   OtherAfter removal of the solid
2. 2
   Filtrationby filtration
3. 3
   Otherthe filtrate was evaporated under reduced pressure
4. 4
   Otherto give a residue, which
5. 5
   Otherwas chromatographed on silica gel (100 ml)
6. 6
   Washeluting with 0%-5% methanol in dichloromethane
7. 7
   workup.ADDITIONwas added a solution of hydrogen chloride in ethyl acetate (4N, 2 ml)
8. 8
   FiltrationThe resulting precipitate was collected by filtration
9. 9
   Washwashed with diisopropyl ether
10. 10
    Otherdried in vacuo

Procedure

A suspension of 1-acetylpiperazine (0.627 g), 2-chloro-4′-fluoroacetophenone (0.844 g), and potassium hydrogen carbonate (0.735 g) in acetonitrile (12 ml) was stirred at ambient temperature for 3 days. After removal of the solid by filtration, the filtrate was evaporated under reduced pressure to give a residue, which was chromatographed on silica gel (100 ml) eluting with 0%-5% methanol in dichloromethane. The objective compound of the free form was taken up into ethyl acetate (2 ml) and to the solution was added a solution of hydrogen chloride in ethyl acetate (4N, 2 ml). The resulting precipitate was collected by filtration, washed with diisopropyl ether, and dried in vacuo to give 1-acetyl-4-(4-fluorophenylcarbonylmethyl)-piperazine hydrochloride (1.47 g).

Source