N,N,N',N'-Tetramethylethylenediamine → 4,4'-Didodecyl-2,2'-bithiophene

HRID 1257977Notes

Reaction equation

HRID 1257977 reaction equation
[Li][CH2:2][CH2:3][CH2:4][CH3:5].[CH2:6]([C:18]1[CH:22]=[CH:21][S:20][CH:19]=1)[CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH3:17].CN(C)[CH2:25][CH2:26]N(C)C>CCOCC>[CH2:2]([C:18]1[CH:25]=[C:26]([C:21]2[S:20][CH:19]=[C:18]([CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH2:13][CH2:14][CH2:15][CH2:16][CH3:17])[CH:22]=2)[S:20][CH:19]=1)[CH2:3][CH2:4][CH2:5][CH2:6][CH2:7][CH2:8][CH2:9][CH2:10][CH2:11][CH2:12][CH3:13]

Participants

5

Procedure

n-BuLi (7.04 mL, 2.5 M in hexanes) was added dropwise to a stirring solution of 3-dodecylthiophene (4.000 g, 15.8 mmol) and N,N,N′,N′-tetramethylethylenediamine (2.75 mL, 17.6 mmol) in 80.0 mL of dry ether at −78° C. The solution was then warmed to room temperature and refluxed for 1 hour. After the solution was cooled to −78° C., CuCl2 (2.640 g, 19.6 mmol) was added in one portion. The reaction mixture was stirred overnight, during which time the temperature rose to room temperature. The reaction mixture was quenched with water and the resulting mixture was extracted with chloroform. The combined organic layers were washed with water, dried over MgSO4 and filtered, and the filtrate was concentrated to dryness. The crude product was purified by column chromatography on silica gel with hexanes as the eluent to yield a mixture of 4,4′- and 3,3′-didodecylthiophene (˜15% of the mixture by 1H NMR). Recrystallization from an acetone:ethanol (1:1) mixture gave 4,4′-didodecyl-2,2′-bithiophene (25) as a white solid (2.200 g, 55% yield). 1H NMR (CDCl3): δ 0.91 (t, 6H), 1.33 (m, 36H), 1.66 (q, 4H), 2.60 (t, 4H), 6.80 (s, 2H), 7.01 (s, 2H) ppm.

Workup

  1. temperaturerefluxed for 1 hour
  2. temperatureAfter the solution was cooled to −78° C.
  3. customrose to room temperature
  4. customThe reaction mixture was quenched with water
  5. extractionthe resulting mixture was extracted with chloroform
  6. washThe combined organic layers were washed with water
  7. dry with materialdried over MgSO4
  8. filtrationfiltered
  9. concentrationthe filtrate was concentrated to dryness
  10. customThe crude product was purified by column chromatography on silica gel with hexanes as the eluent
  11. customto yield
  12. customRecrystallization from an acetone:ethanol (1:1) mixture

Sources & evidence

ORD record
ord-9cec48a6b1594ebe922be8595489fd90
Source dataset
uspto-grants-2013_06
Patent number
USRE044304E1

Reaction notes

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