Benzimidazole → 1-[4-(Trimethylsilyl)phenyl]-1H-benzimidazole

HRID 493023Notes

Reaction equation

HRID 493023 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Si:8]([CH3:11])([CH3:10])[CH3:9])=[CH:4][CH:3]=1.[N:12]1[C:16]2[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=2[NH:14][CH:13]=1.C(=O)([O-])[O-].[K+].[K+].C1OCCOCCOCCOCCOCCOC1>C1C2C(=CC=CC=2)CCC1.[Cu]>[CH3:9][Si:8]([CH3:11])([CH3:10])[C:5]1[CH:6]=[CH:7][C:2]([N:12]2[C:16]3[CH:17]=[CH:18][CH:19]=[CH:20][C:15]=3[N:14]=[CH:13]2)=[CH:3][CH:4]=1

Participants

7

Reactant 4

HCID 5798BenzimidazoleHCID 11430Potassium CarbonateHCID 2855718-Crown-6HCID 138897Silane, (4-bromophenyl)trimethyl-

Product 1

HCID 688793281-[4-(Trimethylsilyl)phenyl]-1H-benzimidazoleYield 81.9%

Reagents, catalysts & solvents 2

HCID 23978CopperCatalystHCID 8404TetralinSolvent

Procedure

To a 1L 3-neck flask equipped with a mechanical stir arm was added 14.5 g (65.1 mmol) of 1-bromo-4-trimethylsilylbenzene, 9.2 g (78.1 mmol) of benzimidazole, 9.1 g (143 mmol) of copper power, 31.4 g (228 mmol) of potassium carbonate, and 1.7 g (6.5 mmol) of 18-crown-6. These chemicals were stirred vigorously in 400 mL tetrahydronaphthalene at 180° C. under N2 atmosphere. After 20 hours of heating, the mixture was filtered warm. The solids on the funnel were repeatedly washed with dichloromethane to remove all organic products as filtrate. The mother liquor was then evaporated in vacuo and pooled with a small batch of crude material from a previous reaction. This residue was purified by distilling on a Kugelrohr apparatus twice. At 160° C., the removal of organic impurities was evidenced. At 200° C. the product distilled. Purification gave 14.2 g N-(p-trimethylsilylphenyl)benzimidazole as a white solid.

Workup

  1. temperatureAfter 20 hours of heating
  2. filtrationthe mixture was filtered
  3. temperaturewarm
  4. washThe solids on the funnel were repeatedly washed with dichloromethane
  5. customto remove all organic products as filtrate
  6. customThe mother liquor was then evaporated in vacuo
  7. custompooled with a small batch of crude material from a previous reaction
  8. customThis residue was purified
  9. distillationby distilling on a Kugelrohr apparatus twice
  10. customAt 160° C., the removal of organic impurities
  11. distillationAt 200° C. the product distilled
  12. customPurification

Sources & evidence

ORD record
ord-45a4fdbd65b54430adc6709204fd91fd
Source dataset
uspto-grants-2009_05
Patent number
US07534505B2

Reaction notes

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