5-Nitrofurfural → HCID 178519730, compound

HRID 1696643Notes

Reaction equation

HRID 1696643 reaction equation
[F:1][C:2]1[CH:3]=[CH:4][C:5]2[N:9]=[C:8]([SH:10])[NH:7][C:6]=2[C:11]=1[F:12].[H-].[Na+].[N+]([C:18]1[O:22][C:21]([CH:23]=[O:24])=[CH:20][CH:19]=1)([O-])=O>O1CCCC1>[F:1][C:2]1[CH:3]=[CH:4][C:5]2[N:9]=[C:8]([S:10][C:18]3[O:22][C:21]([CH:23]=[O:24])=[CH:20][CH:19]=3)[NH:7][C:6]=2[C:11]=1[F:12]

Participants

5

Reactant 3

HCID 127745-NitrofurfuralHCID 24758Sodium hydrideHCID 178505459HCID 178505459, compound

Product 1

HCID 178519730HCID 178519730, compoundYield 55.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

6,7-Difluoro-1H-benzimidazole-2-thiol (0.34 g, 1.81 mmol) is suspended into 20 mL of tetrahydrofuran (THF) under argon. Then, 130 mg (2.71 mmol) of sodium hydride are added. The reaction mixture is stirred at room temperature until gas evolution has ceased. 5-Nitro-2-furaldehyde (0.25 g, 1.81 mmol) is then added and the reaction mixture is stirred at room temperature for 3 h, upon which it is poured on ice and extracted twice with ethyl acetate. The organic extracts are combined, washed with brine, dried on magnesium sulfate, filtered and concentrated under reduced pressure. The residue is purified by chromatography on a prepacked 70 g 15-40 μm silica gel cartridge (eluting solvent: dichloromethane/THF from 100/0 to 80/20 v/v; rate: 40 mL/min). The fractions containing the desired product are combined and concentrated to dryness under reduced pressure. The residue is purified by chromatography on a prepacked 30 g 15-40 μm silica gel cartridge (eluting solvent: dichloromethane/methanol from 100/0 to 95/5 v/v; rate: 20 mL/min). The fractions containing the desired product are combined and concentrated to dryness under reduced pressure. 0.28 g of 5-(6,7-difluoro-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde is obtained as a pale yellow meringue. LCMS-DAD-ELSD: 281(+): [M+H]+.

Workup

  1. stirringthe reaction mixture is stirred at room temperature for 3 h, upon which it
  2. additionis poured on ice
  3. extractionextracted twice with ethyl acetate
  4. washwashed with brine
  5. customdried on magnesium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe residue is purified by chromatography on a prepacked 70 g 15-40 μm silica gel cartridge (eluting solvent: dichloromethane/THF from 100/0 to 80/20 v/v; rate: 40 mL/min)
  9. additionThe fractions containing the desired product
  10. concentrationconcentrated to dryness under reduced pressure
  11. customThe residue is purified by chromatography on a prepacked 30 g 15-40 μm silica gel cartridge (eluting solvent: dichloromethane/methanol from 100/0 to 95/5 v/v; rate: 20 mL/min)
  12. additionThe fractions containing the desired product
  13. concentrationconcentrated to dryness under reduced pressure

Sources & evidence

ORD record
ord-e67178828c70441f999dafee5c215839
Source dataset
uspto-grants-2012_04
Patent number
US08163768B2

Reaction notes

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