反应 #47278

反应方程式

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

收率 93.3%

溶剂

ethyl acetate

heptane

heptane

反应条件

后处理

1. 1
   workup.ADDITIONwas added
2. 2
   workup.STIRRINGthe resulting mixture stirred at room temperature overnight
3. 3
   其他the organic layer was separated
4. 4
   洗涤washed with water (3×600 mL)
5. 5
   浓缩The mixture was concentrated under vacuum
6. 6
   其他to provide a yellow oil which
7. 7
   浓缩The mixture was concentrated
8. 8
   其他to remove any remaining ethyl acetate and heptane (500 mL)
9. 9
   workup.ADDITIONwas added once more
10. 10
    其他crystallization
11. 11
    过滤The thick white suspension was filtered
12. 12
    洗涤washed with heptane, and suction
13. 13
    其他dried

实验过程

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.

来源