Water → 5-(6-chloro-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde

HRID 1696654Notes

Reaction equation

HRID 1696654 reaction equation
[Cl:1][C:2]1[CH:11]=[CH:10][C:5]2[N:6]=[C:7]([SH:9])[NH:8][C:4]=2[CH:3]=1.[H-].[Na+].[N+]([C:17]1[O:21][C:20]([CH:22]=[O:23])=[CH:19][CH:18]=1)([O-])=O.O>O1CCCC1>[Cl:1][C:2]1[CH:11]=[CH:10][C:5]2[N:6]=[C:7]([S:9][C:17]3[O:21][C:20]([CH:22]=[O:23])=[CH:19][CH:18]=3)[NH:8][C:4]=2[CH:3]=1

Participants

6

Reactant 4

HCID 962WaterHCID 127745-NitrofurfuralHCID 24758Sodium hydrideHCID 178527787HCID 178527787, compound

Product 1

HCID 866238815-(6-chloro-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehydeYield 88%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent3×

Procedure

Aldehyde intermediate preparation: 5-Chloro-2-mercaptobenzimidazole (1.5 g, 8.12 mmol) dissolved in 10 ml of anhydrous tetrahydrofuran is added dropwise to a suspension of sodium hydride (60% dispersion in mineral oil, 0.325 g, 8.12 mmol) in anhydrous tetrahydrofuran (20 ml) at 10° C. over a 15 minute period. The reaction mixture is stirred for 2 hours at room temperature. Then 5-nitro-2-furaldehyde (1.146 g, 8.12 mmol) dissolved in 20 ml of anhydrous tetrahydrofuran is added dropwise over a 15 minute period and the reaction mixture is stirred at room temperature for an additional 16 hour period. The reaction mixture is then poured into 300 ml of water and extracted twice with 150 ml of ethyl acetate. The combined organic extracts are dried over MgSO4 and concentrated under reduced pressure. The residue is purified on a silica gel column (120 g) eluted with a mixture of cyclohexane and ethyl acetate (80/20, v/v) to yield 1.9 g of 5-(6-chloro-1H-benzimidazol-2-ylsulfanyl)-furan-2-carbaldehyde. Yield=88%. Analytical LC/MS (method B): retention time=3.40 min., m/z=278.95/1Cl (positive ion mode).

Workup

  1. additionis added dropwise over a 15 minute period
  2. stirringthe reaction mixture is stirred at room temperature for an additional 16 hour period
  3. extractionextracted twice with 150 ml of ethyl acetate
  4. dry with materialThe combined organic extracts are dried over MgSO4
  5. concentrationconcentrated under reduced pressure
  6. customThe residue is purified on a silica gel column (120 g)
  7. washeluted with a mixture of cyclohexane and ethyl acetate (80/20

Sources & evidence

ORD record
ord-321b1f10f2b74c64860c7dc7032d946f
Source dataset
uspto-grants-2012_04
Patent number
US08163768B2

Reaction notes

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