Boron trifluoride etherate → HCID 21332550, compound

HRID 1390529Notes

Reaction equation

HRID 1390529 reaction equation
B(F)(F)F.CCO[CH2:8][CH3:9].C([CH2:13][SiH:14]([C:21]1[CH:26]=[CH:25]C=CC=1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)C=C.[BH4-].[Na+].[Br:29]Br.C[O-].[Na+].C(=O)([O-])[O-].[K+].[K+].O1[CH2:44][CH2:43][CH2:42][CH2:41]1>C1CCCCC1.CO>[Br:29][CH2:25][CH2:26][CH2:21][Si:14]([CH3:13])([C:9]1[CH:8]=[CH:44][CH:43]=[CH:42][CH:41]=1)[C:15]1[CH:16]=[CH:17][CH:18]=[CH:19][CH:20]=1

Participants

10

Reactant 7

HCID 8000Boron trifluoride etherateHCID 8028Tetrahydrofuran2×HCID 11430Potassium CarbonateHCID 24408BromineHCID 4311764Sodium borohydrideHCID 10942334Sodium MethoxideHCID 92011180HCID 92011180, compound

Product 1

HCID 21332550HCID 21332550, compoundYield 49.5%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8078CyclohexaneSolvent

Procedure

To obtain 3-(bromopropyl)methyldiphenylsilane from allylmethyldiphenylsilane, a solution (150 ml) of 29.6 g (208.3 mol) of boron trifluoride etherate in dry tetrahydrofuran was added over a 1 hr period, with stirring, to 350 ml of a tetrahydrofuran solution of 119 g (0.50 mol) of allylmethyldiphenylsilane and 5.94 g (0.156 mol) of sodium borohydride. The reaction mixture was heated at reflux for 2.5 hrs and then 10 ml of methanol was added. Then, 27.3 ml (0.50 mol) of bromine and sodium methoxide solution (from 14.4 g, 0.625 mol of sodium and 300 mol of methanol) were added simultaneously at such a rate as to maintain a yellow color in the reaction mixture. The reaction temperature was kept at 25°-30° by means of an ice bath. The reaction mixture was poured into a mixture of 250 ml of 50% potassium carbonate and 250 ml of cyclohexane. The mixture was agitated until the strong yellow color faded. The layers were separated and the aqueous layer was extracted with three 100 ml portions of cyclohexane. The combined organic layers were washed with three 300 ml portions of water and with 150 ml of saturated sodium chloride, dried over potassium carbonate, and distilled to give 79 g (49.5%) of (3-bromopropyl) methyldiphenylsilane, mp.176°-210° (0.3 mm).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 2.5 hrs
  3. temperatureto maintain a yellow color in the reaction mixture
  4. customThe reaction temperature was kept at 25°-30° by means of an ice bath
  5. customThe layers were separated
  6. extractionthe aqueous layer was extracted with three 100 ml portions of cyclohexane
  7. washThe combined organic layers were washed with three 300 ml portions of water and with 150 ml of saturated sodium chloride
  8. dry with materialdried over potassium carbonate
  9. distillationdistilled

Sources & evidence

ORD record
ord-953d33328fe44a499d26bbac9883d396
Source dataset
uspto-grants-1979_02
Patent number
US04139403

Reaction notes

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