Benzimidazole → 3-(1H-1,3-benzodiazol-1-yl)propan-1-amine

HRID 915681Notes

Reaction equation

HRID 915681 reaction equation
[H-].[Na+].[N:3]1[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[NH:5][CH:4]=1.Br.Br[CH2:14][CH2:15][CH2:16][NH2:17]>O1CCCC1>[N:3]1([CH2:14][CH2:15][CH2:16][NH2:17])[C:7]2[CH:8]=[CH:9][CH:10]=[CH:11][C:6]=2[N:5]=[CH:4]1

Participants

5

Reactant 3

HCID 5798BenzimidazoleHCID 24758Sodium hydride2×HCID 787013-Bromopropylamine hydrobromide

Product 1

HCID 39208493-(1H-1,3-benzodiazol-1-yl)propan-1-amineYield 26.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Prepare a suspension of sodium hydride (812 mg, 20 mmol) in tetrahydrofuran (50 mL). Add benzimidazole (2 g, 16.9 mmol) under nitrogen. Reflux the mixture for 1 hour. At the same time, add 3-bromopropylamine hydrobromide (3.7 g, 16.9 mmol) to a suspension of sodium hydride (676 mg, 16.9 mmol) under nitrogen and reflux the mixture for 1 hour. Combine the two mixtures and reflux for 2 hours. Filter the reaction mixture, concentrate the filtrate to an oil, basify with sodium hydroxide and extract with ethyl acetate (3×50 mL). Concentrate the combined organic layers to an oil. Perform chromatography (silica gel, 9:1 methylene chloride/MeOH) to afford the title compound (780 mg) MS: m/e=176 (MH+)

Workup

  1. customPrepare
  2. temperatureReflux the mixture for 1 hour
  3. temperaturereflux the mixture for 1 hour
  4. temperaturereflux for 2 hours
  5. filtrationFilter the reaction mixture
  6. concentrationconcentrate the filtrate to an oil
  7. extractionbasify with sodium hydroxide and extract with ethyl acetate (3×50 mL)
  8. concentrationConcentrate the combined organic layers to an oil

Sources & evidence

ORD record
ord-1093ad96cd504d3c8699264920a5c53c
Source dataset
uspto-grants-2007_09
Patent number
US07265246B2

Reaction notes

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