Tetramethoxysilane → HCID 12135717, compound

HRID 1743275Notes

Reaction equation

HRID 1743275 reaction equation
[Mg].Br[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][C:4]=1[CH2:9][CH3:10].[CH2:11]([Si:16](OC)([O:19][CH3:20])[O:17][CH3:18])[CH2:12][CH:13]([CH3:15])[CH3:14].C([Mg]Br)CC(C)C.CO[Si](OC)(OC)OC>O.CCOCC>[CH2:9]([C:4]1[CH:5]=[CH:6][CH:7]=[CH:8][C:3]=1[Si:16]([CH2:11][CH2:12][CH:13]([CH3:15])[CH3:14])([O:19][CH3:20])[O:17][CH3:18])[CH3:10]

Participants

8

Reactant 5

HCID 12682TetramethoxysilaneHCID 160891-Bromo-2-ethylbenzeneHCID 5462224MagnesiumHCID 21924134HCID 21924134, compoundHCID 178418529HCID 178418529, compound

Product 1

HCID 12135717HCID 12135717, compoundYield 35.6%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 3283Diethyl EtherSolvent

Procedure

A 1000 mL round bottomed flask was charged with magnesium turnings (1.97 g, 81.0 mmol, Aldrich) and ether (500 mL, Aldrich). Bromo-2-ethylbenzene (14.0 mL, 101 mmol, Aldrich) was added over 30 minutes. The reaction stirred for three hours at room temperature and became dark brown in color. The contents were refluxed for one hour. The contents were cooled to 0° C. and isoamyl-trimethoxysilane (15.9 g, 82.8 mmol, previously prepared by reaction between isoamyl magnesiumbromide and tetramethylortho-silicate) was added over 25 minutes. The reaction was stirred at room temperature overnight (18 hours) during which time a white precipitate formed. The contents were poured into water (500 mL), the layers separated and the product extracted into ether (3×150 mL). The combined organic portions were dried (MgSO4), filtered and the solvent removed via rotary evaporation providing 29.6 g crude material. Distillation under reduced pressure (b.p. 109° C., 1.1 mm Hg) produced (2-ethylphenyl)-3-methylbutyl-dimethoxysilane (7.68 g, 28.8 mmol, 35.6% yield); C15H26SiO2 (Mw=266.45); 1H NMR (CDCl3) δ 7.7 (m, 1H), 7.3 (m, 1H), 7.2 (m, 2H), 3.5 (s, 6H), 2.8 (q, 2H), 1.4 (m, 1H), 1.2 (m, 5H), 0.8 (m, 8H); 13C NMR (CDCl3) δ 150.5, 135.9, 131.2, 130.3, 128.0, 124.9, 50.3, 31.5, 30.7, 28.6, 21.9, 16.1, 10.9; IR (capillary film) ν 3054, 2974, 1590, 1467, 1370, 1200, 1118, 1023, 936, 874, 803, MS m/z (relative abundance) 266 (0.02), 195 (100), 163 (59.1), 160 (28.8), 133 (25.5), 105 (11.2), 91 (12.3), 59 (18.4).

Workup

  1. temperatureThe contents were refluxed for one hour
  2. temperatureThe contents were cooled to 0° C.
  3. additionwas added over 25 minutes
  4. stirringThe reaction was stirred at room temperature overnight (18 hours) during which time a white precipitate
  5. customformed
  6. customthe layers separated
  7. extractionthe product extracted into ether (3×150 mL)
  8. dry with materialThe combined organic portions were dried (MgSO4)
  9. filtrationfiltered
  10. customthe solvent removed via rotary evaporation
  11. customproviding 29.6 g crude material
  12. distillationDistillation under reduced pressure (b.p. 109° C., 1.1 mm Hg)

Sources & evidence

ORD record
ord-9631b975d7da473c8f19f3592493abb3
Source dataset
uspto-grants-2006_03
Patent number
US07009015B2

Reaction notes

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