Iodine → 1,4-Bis(triethoxysilyl)benzene

HRID 1348504Notes

Reaction equation

HRID 1348504 reaction equation
[Mg].CCO[Si:5]([O:12][CH2:13][CH3:14])([O:9][CH2:10][CH3:11])[O:6][CH2:7][CH3:8].II.Br[C:18]1[CH:23]=[CH:22][C:21](Br)=[CH:20][CH:19]=1>C1COCC1>[CH2:13]([O:12][Si:5]([O:6][CH2:7][CH3:8])([O:9][CH2:10][CH3:11])[C:18]1[CH:23]=[CH:22][C:21]([Si:5]([O:12][CH2:13][CH3:14])([O:9][CH2:10][CH3:11])[O:6][CH2:7][CH3:8])=[CH:20][CH:19]=1)[CH3:14]

Participants

6

Reactant 4

HCID 807IodineHCID 6517TetraethoxysilaneHCID 78041,4-DibromobenzeneHCID 5462224Magnesium

Product 1

HCID 114950751,4-Bis(triethoxysilyl)benzeneYield 43%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

A mixture of magnesium turnings (15 g) and TEOS (450 mL, 2 mol) in THF (300 mL) were placed under nitrogen in a 1 L three-neck round bottom flask equipped with magnetic stir bar, condenser, and addition funnel. A small crystal of iodine was added and the mixture was brought to reflux. A solution of 1,4-dibromobenzene (48 g, 204 mmol) in THF (100 mL) was added dropwise over 2 h. Within 30 min of initiating the addition, the reaction became mildly exothermic. The reaction mixture was kept at reflux for 1 h after the completion of the addition of dibromide. The gray-green mixture was allowed to cool to room temperature before the THF was removed in vacuo. Hexane (200 mL) was added to precipitate any remaining magnesium salts in solution and the mixture was quickly filtered under nitrogen to produce a clear, light brown solution. Hexane was removed in vacuo. The product was purified by fractional distillation. The product was recovered as a clear liquid at 130–5° C. (0.2 mmHg) in 43–47% yield. 1H NMR (500 MHz, CDCl3) δ 7.67 (s, 4H, ArH), 3.86 (q, J=7.00 Hz, 12H, OCH2CH3), 1.23 (t, J=7.00 Hz, 18H, ArH); 13C NMR (125 MHz, CDCl3) δ 133.25,57.98, 17.43; 29Si NMR (99 MHz, CDCl3) δ−58.25; MS m/e calc'd for CI (M) C18H34Si2O6: 402.1894, found 402.1886.

Workup

  1. customwere placed under nitrogen in a 1 L three-neck round bottom flask
  2. customequipped with magnetic stir bar, condenser, and addition funnel
  3. temperatureto reflux
  4. additionthe addition
  5. temperatureat reflux for 1 h
  6. customwas removed in vacuo
  7. additionHexane (200 mL) was added
  8. customto precipitate any remaining magnesium salts in solution
  9. filtrationthe mixture was quickly filtered under nitrogen
  10. customto produce a clear, light brown solution
  11. customHexane was removed in vacuo
  12. distillationThe product was purified by fractional distillation
  13. customThe product was recovered as a clear liquid at 130–5° C. (0.2 mmHg) in 43–47% yield

Sources & evidence

ORD record
ord-8c4f58ca98eb4b49bc646345388bcd5a
Source dataset
uspto-grants-2007_05
Patent number
US07211192B2

Reaction notes

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