反应详情

温度

0 °C

A solution of 2-(thiophen-3-yl)-1,3-dioxolane (10.00 g, 64.02 mmol) in anhydrous tetrahydrofuran (50 ml) was cooled in a dry ice-methanol bath, and n-butyllithium hexane solution (1.59M, 44.3 ml, 70.4 mmol) was added dropwise while preventing the reaction mixture from exceeding −55° C. After stirring for 1 hr, chlorotrimethylsilane (8.94 ml, 70.4 mmol) was added dropwise while preventing the reaction mixture from exceeding −60° C. After stirring at −78 to −60° C. for 30 min, the mixture was warmed to 0° C. over 30 min and stirred at 0° C. for 1 hr. The reaction mixture was cooled again in a dry ice-methanol bath, and n-butyllithium hexane solution (1.59M, 46.3 ml, 73.6 mmol) was added dropwise while preventing the reaction mixture from exceeding −60° C. After stirring at −78 to −60° C. for 1 hr, N,N-dimethylformamide (12.4 ml, 160 mmol) was added dropwise, and the mixture was further stirred for 1 hr. The mixture was warmed to 0° C. over 1 hr, and saturated aqueous ammonium chloride solution (100 ml) was added. The mixture was washed 3 times with ethyl acetate, and the combined organic layer was washed twice with 0.2M hydrochloric acid and once with saturated brine. To the organic layer were added anhydrous magnesium sulfate and activated carbon, and the mixture was stirred for 5 min and filtered. The filtrate was concentrated under reduced pressure to give 4-(1,3-dioxolan-2-yl)-5-(trimethylsilyl)thiophene-2-carbaldehyde (16.09 g, 62.76 mmol, yield 98.0%) as an orange oil.

1. customfrom exceeding −55° C
2. customfrom exceeding −60° C
3. stirringAfter stirring at −78 to −60° C. for 30 min
4. stirringstirred at 0° C. for 1 hr
5. temperatureThe reaction mixture was cooled again in a dry ice-methanol bath
6. customfrom exceeding −60° C
7. stirringAfter stirring at −78 to −60° C. for 1 hr
8. stirringthe mixture was further stirred for 1 hr
9. temperatureThe mixture was warmed to 0° C. over 1 hr
10. washThe mixture was washed 3 times with ethyl acetate
11. washthe combined organic layer was washed twice with 0.2M hydrochloric acid and once with saturated brine
12. additionTo the organic layer were added anhydrous magnesium sulfate and activated carbon
13. stirringthe mixture was stirred for 5 min
14. filtrationfiltered
15. concentrationThe filtrate was concentrated under reduced pressure