반응 #70957

반응 방정식

1,2-bis(2,5-dimethyl-3-thienyl)ethanedione

benzene

Potassium t-butoxide

benzene

→

25

수율 25.0%

3,4-bis(2,5-dimethyl-3-thienyl)cyclohexadiene

수율 25.0%

반응 조건

후처리

1. 1
   온도The resulting orange solution was heated
2. 2
   온도to reflux
3. 3
   workup.STIRRINGThe reaction mixture was stirred
4. 4
   온도at reflux for 20 min, at which point the heating mantle
5. 5
   기타was removed
6. 6
   온도to cool to room temperature
7. 7
   기타The reaction was quenched by the addition of water (50 mL)
8. 8
   추출extracted with Et2O (3×50 mL)
9. 9
   세척washed with brine
10. 10
    건조dried over MgSO4
11. 11
    여과filtered
12. 12
    기타The solvent was removed under reduced pressure
13. 13
    기타the residue was purified by column chromatography through silica (1:9 EtOAc:hexanes)

실험 절차

Potassium t-butoxide (163 mg, 1.45 mmol) was added to a suspension of 1,4-butanebis(triphenylphosphonium)dibromide (537 mg, 0.725 mmol) in benzene (50 mL). The reaction was stirred for 45 min at room temperature. The resulting orange solution was heated to reflux and treated drop-wise with a solution of 1,2-bis(2,5-dimethyl-3-thienyl)ethanedione 23 (202 mg, 0.72 mmol) in benzene (25 mL). The reaction mixture was stirred at reflux for 20 min, at which point the heating mantle was removed and the reaction was allowed to cool to room temperature. The reaction was quenched by the addition of water (50 mL) and extracted with Et2O (3×50 mL). The organic extracts were combined, washed with brine, dried over MgSO4 and filtered. The solvent was removed under reduced pressure and the residue was purified by column chromatography through silica (1:9 EtOAc:hexanes) to yield 55 mg (25%) of 25 as a white solid. Mp=55-57° C. 1H NMR (CDCl3): δ=6.13 (s, 2H), 5.88 (m, 2H), 2.26 (m, 10H), 2.14 (s, 6H); 13C NMR (CDCl3) δ=137.8, 134.4, 133.9, 131.6, 127.4, 126.7, 22.7, 15.1, 14.0. MS (EI): m/z=300 (M+).

출처