反应详情

温度

10 °C

Under a dry argon atmosphere, a stirred solution of 3.0 g (0.017 mole) of 2-(2,2-dichloroethenyl)thiophene and 1.33 g (0.017 mole) of acetyl chloride in 10 ml of methylene chloride was cooled to -20° C. During a five minute period 2.24 g (0.017 mole) of anhydrous aluminum chloride was added. The reaction mixture was warmed to 10° C., then poured into 250 ml of cold water. The resultant mixture was extracted with two 100 ml portions of diethyl ether. The combined extracts were washed with 30 ml of a dilute sodium carbonate solution, dried with anhydrous sodium sulfate and filtered. The solvent was evaporated to give a brown solid. The solid was dissolved in a small amount of toluene and subjected to column chromatography on 100 g of silica gel using n-heptane followed by a solution of 10% ethylacetate in n-heptane as eluant. A white solid was obtained and recrystallized from n-heptane to give 2.5 g of crude product. A sample of the crude product was sublimed at 90° C./7 pa to yield 5-(2,2-dichloroethenyl)-2-thienylethanone; mp 81°-85° C. The nmr and ir spectra were consistent with the proposed structure.

1. extractionThe resultant mixture was extracted with two 100 ml portions of diethyl ether
2. washThe combined extracts were washed with 30 ml of a dilute sodium carbonate solution
3. dry with materialdried with anhydrous sodium sulfate
4. filtrationfiltered
5. customThe solvent was evaporated
6. customto give a brown solid
7. customA white solid was obtained
8. customrecrystallized from n-heptane
9. customto give 2.5 g of crude product
10. customwas sublimed at 90° C.