Reaktion #505460

Reaktionsgleichung

1,1-dimethylethyl(2R)-2-methyl-1-piperazinecarboxylate

DIPEA

HCl

1,4-dioxane

4-(trifluoromethyl)benzenesulfonyl chloride

→

title compound

Ausbeute 83.0%

(3R)-3-Methyl-1-{[4-(trifluoromethyl)phenyl]sulfonyl}piperazine

Ausbeute 83.0%

Lösungsmittel

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   Waschenthen washed with water (250 ml)
2. 2
   Sonstigedried on a phase separation cartridge
3. 3
   Einengenconcentrated in vacuo
4. 4
   workup.DISSOLUTIONThe obtained product was dissolved in 1,4-dioxane (60 ml)
5. 5
   EinengenThe mixture was concentrated in vacuo
6. 6
   workup.DISSOLUTIONthen dissolved in EtOAc (150 ml)
7. 7
   Waschenwashed with 2N aq. NaOH solution (200 ml)
8. 8
   Sonstigethen dried on a phase separation cartridge
9. 9
   Einengenconcentrated in vacuo
10. 10
    workup.DISSOLUTIONThe product was then dissolved in EtOAc (100 ml)
11. 11
    Extraktionextracted with 2M HCl (2×200 ml)
12. 12
    workup.ADDITION2M NaOH solution were added to aqueous layer until basic pH
13. 13
    Extraktionthe product was extracted with EtOAc (500 ml)
14. 14
    SonstigeThe organic layer was dried on a phase separation cartridge
15. 15
    Einengenconcentrated in vacuo

Vorschrift

To a solution of 1,1-dimethylethyl(2R)-2-methyl-1-piperazinecarboxylate (2.95 g, 14.7 mmol) in DCM (120 ml) was added DIPEA (5.40 ml, 30.9 mmol) and then 4-(trifluoromethyl)benzenesulfonyl chloride (3.96 g, 16.2 mmol). The reaction mixture was stirred 2.5 hours at rt then washed with water (250 ml), dried on a phase separation cartridge and concentrated in vacuo. The obtained product was dissolved in 1,4-dioxane (60 ml) and treated with 4M HCl in 1,4-dioxane (18.4 ml, 73.6 mmol) overnight. The mixture was concentrated in vacuo then dissolved in EtOAc (150 ml), washed with 2N aq. NaOH solution (200 ml) then dried on a phase separation cartridge and concentrated in vacuo. The product was then dissolved in EtOAc (100 ml) and extracted with 2M HCl (2×200 ml). 2M NaOH solution were added to aqueous layer until basic pH then the product was extracted with EtOAc (500 ml). The organic layer was dried on a phase separation cartridge and concentrated in vacuo to give the title compound (3.76 g).

Quelle