反应详情

To a solution of 2-(3-methylthiophen-2-yl)-1,3-dioxolane (3.198 g, 18.79 mmol) in anhydrous tetrahydrofuran (30 ml) was added dropwise 1.55M butyllithium hexane solution (12.1 ml, 18.8 mmol) at −78° C. After stirring for 30 min, anhydrous N,N-dimethylformamide (4.36 ml, 56.3 mmol) was added dropwise. After stirring at −78° C. for 1 hr, the reaction mixture was warmed, saturated aqueous ammonium chloride was added, and the mixture was extracted twice with ethyl acetate. The combined organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure, and the residue was purified by silica gel column chromatography (FUJI SILYSIA CHEMICAL LTD. BW-300SP 80 g, ethyl acetate:hexane=1:5) to give 5-(1,3-dioxolan-2-yl)-4-methylthiophene-2-carbaldehyde (3.309 g, 16.69 mmol, yield 88.8%) as a brown oil.

1. stirringAfter stirring at −78° C. for 1 hr
2. temperaturethe reaction mixture was warmed
3. extractionthe mixture was extracted twice with ethyl acetate
4. washThe combined organic layer was washed with saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. concentrationconcentrated under reduced pressure
7. customthe residue was purified by silica gel column chromatography (FUJI SILYSIA CHEMICAL LTD. BW-300SP 80 g, ethyl acetate:hexane=1:5)