反应详情

温度

160 °C

12.5 mL of water was added to 237.5 mL of tert-butanol, then nitrogen gas was blown thereinto for 5 minutes to remove dissolved oxygen thereby to prepare a reaction solvent. Into a 500 mL autoclave, 50.0 g of 1-chloro-3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)benzene, 28.5 g of sodium carbonate, 1.5 g of 1,4-bis(diphenylphosphino)butane, the above reaction solvent, and 1.5 g of 5% Pd/C were introduced, and the autoclave was closed. With stirring, nitrogen flushing (5.0 MPa) was carried out twice, followed by flushing with carbon monoxide (5.0 MPa) twice. Finally, carbon monoxide was filled (2.5 MPa). By an electric furnace, the autoclave was heated to 160° C., followed by stirring for 7 hours (300 rps). After cooling to room temperature, carbon monoxide gas remaining in the autoclave was removed. The content was poured into water and ethyl acetate, and insolubles were filtered off by celite. Then, the filtrate was subjected to liquid separation, and the aqueous layer was washed twice with ethyl acetate. The aqueous layer was acidified with hydrochloric acid (pH=1) and then extracted with ethyl acetate. The organic layer was washed with a saturated sodium chloride aqueous solution and dried over sodium sulfate, and then, the solvent was distilled off under reduced pressure to obtain 3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)benzoic acid (50.1 g). Further, the obtained solid was washed with 150 mL of hexane and then collected by filtration and dried under reduced pressure to obtain 3-(2-methoxyethoxy)-2-methyl-4-(methylsulfonyl)benzoic acid (48.1 g) as white solid.

1. customfor 5 minutes to remove
2. dissolutiondissolved oxygen
3. customto prepare a reaction solvent
4. customthe autoclave was closed
5. customby flushing with carbon monoxide (5.0 MPa) twice
6. additionFinally, carbon monoxide was filled (2.5 MPa)
7. stirringby stirring for 7 hours (300 rps)
8. temperatureAfter cooling to room temperature
9. customwas removed
10. additionThe content was poured into water and ethyl acetate, and insolubles
11. filtrationwere filtered off by celite
12. customThen, the filtrate was subjected to liquid separation
13. washthe aqueous layer was washed twice with ethyl acetate
14. extractionextracted with ethyl acetate
15. washThe organic layer was washed with a saturated sodium chloride aqueous solution
16. dry with materialdried over sodium sulfate
17. distillationthe solvent was distilled off under reduced pressure