反应详情

温度

-20 °C

A solution of 15 g. (79.0 mmol) of 2,4-dimethyl-3-bromothiophene in 120 ml. of dry ether was cooled to -70° C. and 36 ml. of a hexane solution of n-butyl lithium (2.4 molar, 86.4 mmol) were added dropwise. The reaction mixture was allowed to warm up to -20° C. for 10 min., cooled again to -70° C. and then quenched by adding dropwise 15 g. (0.205 mol) of dimethylformamide. The mixture was stirred at room temperature overnight, poured into ice water, stirred for 15 min. and extracted four times with ether. The ether phase was washed with saturated sodium chloride solution, dried and evaporated. The resulting oily residue was distilled to yield 2,4-dimethylthiophene-3-carboxaldehyde, b.p. 50°-55° C./0.1 mm.

1. temperaturecooled again to -70° C.
2. customquenched
3. additionby adding dropwise 15 g
4. stirringstirred for 15 min.
5. extractionextracted four times with ether
6. washThe ether phase was washed with saturated sodium chloride solution
7. customdried
8. customevaporated
9. distillationThe resulting oily residue was distilled