Reaktion #71650

Reaktionsgleichung

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

DIPEA

HCl

1,4-dioxane

4-(trifluoromethyl)benzenesulfonyl chloride

→

title compound

Ausbeute 82.8%

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

Ausbeute 82.8%

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 under 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 aq. HCl (2×200 ml)
12. 12
    workup.ADDITION2M aq. NaOH solution was added to the 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 under vacuo

Vorschrift

To a solution of 1,1-dimethylethyl (2R)-2-methyl-1-piperazinecarboxylate (2.95 g, 14.73 mmol) in DCM (120 ml) was added DIPEA (5.40 ml, 30.9 mmol) and then 4-(trifluoromethyl)benzenesulfonyl chloride (3.96 g, 16.20 mmol). The reaction mixture was stirred 2.5 hours at room temperature 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 aq. HCl in 1,4-dioxane (18.41 ml, 73.6 mmol) overnight. The mixture was concentrated under 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 aq. HCl (2×200 ml). 2M aq. NaOH solution was added to the 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 under vacuo to give the title compound (3.76 g).

Quelle