Stannous Chloride → 4,8-Bis(2-ethylhexyl)benzo[1,2-b:4,5-b']dithiophene

HRID 2195095Notes

Reaction equation

HRID 2195095 reaction equation
[Mg].[CH2:2]([CH:4]([CH2:7][CH2:8][CH2:9][CH3:10])[CH2:5]Br)[CH3:3].[S:11]1[CH:15]=[CH:14][C:13]2[C:16](=O)[C:17]3[S:18][CH:19]=[CH:20][C:21]=3[C:22](=O)[C:12]1=2.Cl[Sn]Cl>[Cl-].[Na+].O.C1COCC1>[CH2:2]([CH:4]([CH2:7][CH2:8][CH2:9][CH3:10])[CH2:5][C:16]1[C:17]2[S:18][CH:19]=[CH:20][C:21]=2[C:22]([CH2:5][CH:4]([CH2:2][CH3:3])[CH2:7][CH2:8][CH2:9][CH3:10])=[C:12]2[S:11][CH:15]=[CH:14][C:13]=12)[CH3:3]

Participants

7

Reactant 4

HCID 24479Stannous ChlorideHCID 868042-Ethylhexyl bromideHCID 288478(Benzo(1,2-b:4,5-b)dithiophene-4,8-dione)HCID 5462224Magnesium2×

Product 1

HCID 596092024,8-Bis(2-ethylhexyl)benzo[1,2-b:4,5-b']dithiopheneYield 43.9%

Reagents, catalysts & solvents 2

HCID 8028TetrahydrofuranSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

To a 100 mL flask under nitrogen was added magnesium (656 mg, 27 mmol) and anhydrous THF (10 mL). The mixture was heated under reflux and 2-ethylhexyl bromide (5.6 mL, 30 mmol) was added dropwise. The reaction mixture was kept at refluxing temperatures until all magnesium was consumed. After cooling down, 4,8-dihydrobenzo[1,2-b:4,5-b′]dithiophene-4,8-dione (1.1 g, 5.0 mmol) was added in one portion. After refluxing for 1 hour more, it was cooled down again to room temperature. SnCl2 solution (7.5 g in 19 mL 10% HCl) was slowly added dropwise and then the mixture was kept at 60° C. for 1 hour. After cooling down, brine (11 mL) was added. The organic phase was separated and dried over Na2SO4. The residue after vacuum evaporation was purified by column chromatography with hexane as eluent and gave a pale yellow oil (910 mg, yield 43%). 1H NMR (CDCl3, 500 MHz) δ=7.47 (d, J=6.0 Hz, 2H), 7.45 (d, J=6.0 Hz, 2H), 3.08-3.20 (m, 4H), 1.92-2.04 (m, 2H), 1.13-1.49 (m, 16H), 0.91 (t, J=7.0 Hz, 6H), 0.85 (t, J=7.0 Hz, 6H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux
  3. customwas consumed
  4. temperatureAfter cooling down
  5. temperatureAfter refluxing for 1 hour more
  6. temperatureAfter cooling down
  7. customThe organic phase was separated
  8. dry with materialdried over Na2SO4
  9. customThe residue after vacuum evaporation
  10. customwas purified by column chromatography with hexane as eluent

Sources & evidence

ORD record
ord-6a320779e3ef4dee89cc313e93255bbb
Source dataset
uspto-grants-2012_12
Patent number
US08334456B2

Reaction notes

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