5-Nitrofurfural → HCID 178488111, compound

HRID 1696628Notes

Reaction equation

HRID 1696628 reaction equation
[SH:1][C:2]1[NH:3][C:4]2[CH:10]=[C:9]([O:11][CH3:12])[CH:8]=[CH:7][C:5]=2[N:6]=1.[H-].[Na+].[N+]([C:18]1[O:22][C:21]([CH:23]=[O:24])=[CH:20][CH:19]=1)([O-])=O>O1CCCC1>[CH3:12][O:11][C:9]1[CH:8]=[CH:7][C:5]2[NH:6][C:2]([S:1][C:18]3[O:22][C:21]([CH:23]=[O:24])=[CH:20][CH:19]=3)=[N:3][C:4]=2[CH:10]=1

Participants

5

Reactant 3

HCID 127745-NitrofurfuralHCID 24758Sodium hydrideHCID 178488032HCID 178488032, compound

Product 1

HCID 178488111HCID 178488111, compoundYield 27.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Procedure

2-Mercapto-5-methoxybenzimidazole (1.8 g, 10.0 mmol) is suspended into 25 mL of tetrahydrofuran (THF) under argon. Then, 575 mg (12.0 mmol) of sodium hydride are added. The reaction mixture is stirred at room temperature until gas evolution has ceased. A solution of 5-nitro-2-furaldehyde (1.4 g, 10.0 mmol) in 30 mL of THF is then added dropwise and the reaction mixture is stirred at room temperature for 2 h, upon which it is poured on ice and extracted 3 times with 50 mL of ethyl acetate. The organic extracts are combined, washed with brine, dried on magnesium sulfate, filtered and concentrated under reduced pressure. The residue is triturated in diisopropyl ether and the resulting suspension is stirred for 1 h. The solid is filtered, washed twice with diisopropyl ether and dried. 0.75 g of 5-(5-methoxy-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde is obtained as a pale yellow powder. The filtrate is concentrated under reduced pressure and the residue is purified by chromatography on a prepacked 90 g 15-40 μm silica gel cartridge (eluting solvent: ethyl acetate). The fractions containing the desired product are combined and concentrated to dryness under reduced pressure. 0.92 g of additional 5-(5-methoxy-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde is obtained as a pale yellow powder. mp: 94-99° C.

Workup

  1. stirringthe reaction mixture is stirred at room temperature for 2 h, upon which it
  2. additionis poured on ice
  3. extractionextracted 3 times with 50 mL of ethyl acetate
  4. washwashed with brine
  5. customdried on magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe residue is triturated in diisopropyl ether
  9. stirringthe resulting suspension is stirred for 1 h
  10. filtrationThe solid is filtered
  11. washwashed twice with diisopropyl ether
  12. customdried

Sources & evidence

ORD record
ord-ab15b229a8284bd4ab19b0cbff010a6a
Source dataset
uspto-grants-2012_04
Patent number
US08163768B2

Reaction notes

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