Potassium Iodide → 4,4-Dihexyl-4H-cyclopenta[1,2-b:5,4-b']bisthiophene

HRID 1797766Notes

Reaction equation

HRID 1797766 reaction equation
[S:1]1[CH:5]=[CH:4][C:3]2[CH2:6][C:7]3[CH:11]=[CH:10][S:9][C:8]=3[C:2]1=2.[CH2:12](Br)[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17].[I-].[K+]>CS(C)=O>[CH2:12]([C:6]1([CH2:7][CH2:8][CH2:2][CH2:3][CH2:4][CH3:5])[C:7]2[CH:11]=[CH:10][S:9][C:8]=2[C:2]2[S:1][CH:5]=[CH:4][C:3]1=2)[CH2:13][CH2:14][CH2:15][CH2:16][CH3:17]

Participants

5

Reactant 3

HCID 4875Potassium IodideHCID 81011-BromohexaneHCID 1362324H-Cyclopenta(2,1-b:3,4-b')dithiophene

Product 1

HCID 594268924,4-Dihexyl-4H-cyclopenta[1,2-b:5,4-b']bisthiophene

Reagents, catalysts & solvents 1

HCID 679Dimethyl SulfoxideSolvent

Procedure

To a solution of 4H-Cyclopenta[2,1-b:3,4-b′]dithiophene (CDT) (1.63 g, 9.14 mmol) in dimethyl sulfoxide (50 mL) was added hexyl bromide (3.1 g, 18.9 mmol) and a catalytic amount of potassium iodide (50 mg). The mixture was purged with argon for 10 minutes followed by the slow addition of solid potassium hydroxide (2 g). The now dark green mixture was stirred in the dark at room temperature for 72 hours. The mixture was then poured into de-ionized water (150 mL) and the organic phase extracted with diethyl ether (4×100 mL). The organic phases were collected and washed with brine (100 mL) and a saturated ammonium chloride solution (100 mL). The organic phase was dried over magnesium sulphate, filtered, and concentrated to give the crude product as yellow oil. Purification via flash chromatography with hexanes (monitored at 254 nm, collected at 320 nm) and drying under high vacuum for 48 hours gave pure product as colorless oil. Yield 2.8 g (88%). 1H NMR (500 MHz, CDCl3): δ=7.15 (d, 2H, 3JH-H=5 Hz), 6.94 (d, 2H, 3JH-H=5 Hz), 1.84 (m, 4H, C—CH2), 1.19 (m, 12H, alkyl-CH2), 0.95 (m, 4H, alkyl-CH2), 0.82 (m, 6H, alkyl-CH3).

Workup

  1. customThe mixture was purged with argon for 10 minutes
  2. additionfollowed by the slow addition of solid potassium hydroxide (2 g)
  3. additionThe mixture was then poured into de-ionized water (150 mL)
  4. extractionthe organic phase extracted with diethyl ether (4×100 mL)
  5. customThe organic phases were collected
  6. washwashed with brine (100 mL)
  7. dry with materialThe organic phase was dried over magnesium sulphate
  8. filtrationfiltered
  9. concentrationconcentrated
  10. customto give the crude product as yellow oil
  11. customPurification via flash chromatography with hexanes (monitored at 254 nm, collected at 320 nm)
  12. customdrying under high vacuum for 48 hours
  13. customgave pure product as colorless oil

Sources & evidence

ORD record
ord-430a39f084344f4cab3af2b7f7ac5818
Source dataset
uspto-grants-2013_01
Patent number
US08343382B2

Reaction notes

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