تفاعل #47278

معادلة التفاعل

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

المردود 93.3%

المذيبات

ethyl acetate

heptane

heptane

ظروف التفاعل

المعالجة

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

الإجراء التجريبي

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.

المصدر