反应详情

温度

-70 °C

20.0 G. of 2,4-dibromo-3,5-dimethylthiophene was dissolved in 300 ml. of anhydrous ethyl ether. The resulting solution was cooled to -70° C. With stirring under argon. 32 Ml. of a 2.4 M solution of n-butyl lithium was added slowly and the solution was warmed to -32° C. for 10 minutes and then cooled again to 31 70° C. 7.5 G. of dimethyl disulfide was added slowly while the temperature was maintained at -70° C. The resulting solution was warmed to room termperature and stirred for 2 hours thne poured into ice water, stirred for 15 minutes, and extracted with ethyl ether. The combined ether extracts were washed with water, 5% sodium carbonate, and saturated sodium chloride solution; dried over sodium sulfate, filtered and evaporated to yield 3-bromo-2,4-dimethyl-5-(methylthio)thiophene.

1. temperaturethe solution was warmed to -32° C. for 10 minutes
2. temperaturecooled again to 31 70° C
3. temperaturewas maintained at -70° C
4. temperatureThe resulting solution was warmed to room termperature
5. stirringstirred for 2 hours
6. stirringstirred for 15 minutes
7. extractionextracted with ethyl ether
8. washThe combined ether extracts were washed with water, 5% sodium carbonate, and saturated sodium chloride solution
9. dry with materialdried over sodium sulfate
10. filtrationfiltered
11. customevaporated