Thiophene → 2,5-Diheptylthiophene

HRID 53294

Reaction equation

HRID 53294 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[CH:2]1.[Li][CH2:7][CH2:8][CH2:9][CH3:10].[CH3:11][CH2:12][CH2:13]CCC.Br[CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH3:24]>C1COCC1>[CH2:10]([C:2]1[S:1][C:5]([CH2:18][CH2:19][CH2:20][CH2:21][CH2:22][CH2:23][CH3:24])=[CH:4][CH:3]=1)[CH2:9][CH2:8][CH2:7][CH2:11][CH2:12][CH3:13]

Participants

6

Reactant 4

HCID 8030ThiopheneHCID 8058HexaneHCID 123691-BromoheptaneHCID 178418339Butyllithium

Product 1

HCID 6071142,5-DiheptylthiopheneYield 76%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

In a typical experiment, 2 g (0.024 mole) of thiophene in 50 ml THF (dried over sodium) were treated with 2.5 eq. 1.5M n-BuLi in hexane (0.06 mole, 45 ml) at 0° C. When addition was completed, the mixture was stirred at room temperature for 5 hours. The solution was cooled at 0° C., quenched with 9.5 ml (0.06 mole) of 1-bromoheptane and then stirred at room temperature for 24 hours. The mixture was poured into ice, extracted with ether, dried (MgSO4), and the solvent evaporated. The crude product contains mono and disubstituted thiophene in the ratio 1:2 (by 1H-nmr). The crude product was then treated under the same conditions as above to yield exclusively 2,5-diheptylthiophene (5.1 g, 76%) bp 225°/0.1 mm. 1H-nmr (CDCl3) shows 86.5 (s, 2H); 2.7 (t, 4H); 0.75-2.0 (M, 26H).

Workup

  1. customat 0° C
  2. additionWhen addition
  3. temperatureThe solution was cooled at 0° C.
  4. stirringstirred at room temperature for 24 hours
  5. additionThe mixture was poured into ice
  6. extractionextracted with ether
  7. dry with materialdried (MgSO4)
  8. customthe solvent evaporated
  9. additionThe crude product was then treated under the same conditions as above

Sources & evidence

ORD record
ord-6c498a30fa2a4903a117265bd6877f9c
Source dataset
uspto-grants-1997_04
Patent number
US05618929

Linked notes

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