Reaktion #47278

Reaktionsgleichung

water

((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-methanol

1,4-diazabicyclo[2.2.2]octane

4-chlorobenzenesulfonyl chloride

→

4-chloro-benzenesulfonic acid (S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl ester

Ausbeute 93.3%

Lösungsmittel

ethyl acetate

heptane

heptane

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added
2. 2
   workup.STIRRINGthe resulting mixture stirred at room temperature overnight
3. 3
   Sonstigethe organic layer was separated
4. 4
   Waschenwashed with water (3×600 mL)
5. 5
   EinengenThe mixture was concentrated under vacuum
6. 6
   Sonstigeto provide a yellow oil which
7. 7
   EinengenThe mixture was concentrated
8. 8
   Sonstigeto remove any remaining ethyl acetate and heptane (500 mL)
9. 9
   workup.ADDITIONwas added once more
10. 10
    Sonstigecrystallization
11. 11
    FiltrationThe thick white suspension was filtered
12. 12
    Waschenwashed with heptane, and suction
13. 13
    Sonstigedried

Vorschrift

To a solution of ((R)-2,2-dimethyl-[1,3]dioxolan-4-yl)-methanol (60.00 g, 454.0 mmol) and 1,4-diazabicyclo[2.2.2]octane (63.67 g, 567.6 mmol) in ethyl acetate 600 mL) at 15° C. was added 4-chlorobenzenesulfonyl chloride (100.6 g, 476.7 mmol) and the resulting cloudy solution stirred for 2 h before being warmed to room temperature. The resulting solution was stirred at room temperature for 4 h before cold water (300 mL) was added and the resulting mixture stirred at room temperature overnight. The mixture was diluted with heptane (600 mL) and the organic layer was separated and washed with water (3×600 mL). The mixture was concentrated under vacuum to provide a yellow oil which was treated with heptane (200 mL). The mixture was concentrated to remove any remaining ethyl acetate and heptane (500 mL) was added once more to induce crystallization. The thick white suspension was filtered, washed with heptane, and suction dried to provide 4-chloro-benzenesulfonic acid (S)-2,2-dimethyl-[1,3]dioxolan-4-ylmethyl ester (129.93 g, 93.3%, 98.9% pure HPLC, 99.89% e.e) as a white solid.

Quelle