تفاعل #70957

معادلة التفاعل

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

benzene

Potassium t-butoxide

benzene

→

25

المردود 25.0%

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

المردود 25.0%

ظروف التفاعل

المعالجة

1. 1
   درجة الحرارةThe resulting orange solution was heated
2. 2
   درجة الحرارةto reflux
3. 3
   workup.STIRRINGThe reaction mixture was stirred
4. 4
   درجة الحرارةat reflux for 20 min, at which point the heating mantle
5. 5
   أخرىwas removed
6. 6
   درجة الحرارةto cool to room temperature
7. 7
   أخرىThe reaction was quenched by the addition of water (50 mL)
8. 8
   استخلاصextracted with Et2O (3×50 mL)
9. 9
   غسيلwashed with brine
10. 10
    تجفيفdried over MgSO4
11. 11
    ترشيحfiltered
12. 12
    أخرىThe solvent was removed under reduced pressure
13. 13
    أخرىthe residue was purified by column chromatography through silica (1:9 EtOAc:hexanes)

الإجراء التجريبي

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+).

المصدر