反应详情

温度

-78 °C

2-Methyl-2-(2-thienyl)-1,3-dioxolan (6.6 g) (synthesized in accordance with the method described in Tetrahedron, 41, 3803 (1985)) was dissolved in tetrahydrofuran (200 ml), and N,N,N', N'-tetramethylethylenediamine (5.87 ml) was added. The mixture was cooled to -78° C., and n-butyllithium (1.6M in hexane, 25 ml) was slowly added dropwise. The mixture was stirred at the same temperature for 2 hours, and warmed slowly to room temperature for a period of 2 hours with introducing carbon dioxide gas. The reaction mixture was concentrated under reduced pressure, and 2N hydrochloric acid (200 ml) was added. The mixture was stirred for 3 hours, and precipitated crystals were collected by filtration, washed with water and dried to give 5-acetyl-2-thiophenecarboxylic acid (3.87 g) as crystals.

1. concentrationThe reaction mixture was concentrated under reduced pressure, and 2N hydrochloric acid (200 ml)
2. additionwas added
3. stirringThe mixture was stirred for 3 hours
4. customprecipitated crystals
5. filtrationwere collected by filtration
6. washwashed with water
7. customdried