Reaction #452485

Reaction equation

Thionyl chloride

quinaldinic acid

N-benzylpiperazine

→

title compound

1-benzyl-4-(2-quinolylcarbonyl)piperazine hydrochloride

Solvents

chloroform

acetone

Conditions

Workup

1. 1
   TemperatureAfter the resulting mixture was heated
2. 2
   Temperatureunder reflux
3. 3
   workup.DISTILLATIONthe solvent was distilled off
4. 4
   workup.DISSOLUTIONThe residue was dissolved in acetone (50 ml)
5. 5
   workup.STIRRINGThe thus-obtained mixture was stirred for 1 hour
6. 6
   OtherA deposited precipitate was removed
7. 7
   workup.DISTILLATIONthe solvent was distilled off
8. 8
   workup.DISSOLUTIONThe residue was dissolved in ethyl ether
9. 9
   WashThe resulting solution was washed with an aqueous solution of sodium chloride
10. 10
    Dryingdried over anhydrous magnesium sulfate
11. 11
    workup.DISTILLATIONThe solvent was distilled off
12. 12
    workup.DISSOLUTIONthe residue was dissolved in methanol
13. 13
    workup.ADDITIONfollowed by the addition of concentrated hydrochloric acid (5 ml) for acidification
14. 14
    workup.DISTILLATIONThe solvent was distilled off
15. 15
    Otherthe thus-obtained residue was crystallized from a mixed solvent of ethanol and methanol

Procedure

Thionyl chloride (6 ml) was added to a suspension of quinaldinic acid (3.463 g, 20 mmol) in chloroform (40 ml). After the resulting mixture was heated under reflux and stirring for 6 hours, the solvent was distilled off. The residue was dissolved in acetone (50 ml), followed by the addition of a solution of N-benzylpiperazine (10.576 g, 60 mmol) in acetone (50 ml). The thus-obtained mixture was stirred for 1 hour. A deposited precipitate was removed, and the solvent was distilled off. The residue was dissolved in ethyl ether. The resulting solution was washed with an aqueous solution of sodium chloride, and then dried over anhydrous magnesium sulfate. The solvent was distilled off, and the residue was dissolved in methanol, followed by the addition of concentrated hydrochloric acid (5 ml) for acidification. The solvent was distilled off and the thus-obtained residue was crystallized from a mixed solvent of ethanol and methanol, whereby 7.166 g of the title compound were obtained as white powder (yield: 97.5%).

Source