Imidazole → 1-(2-fluoro-4-nitrophenyl)-1H-imidazole

HRID 1955108Notes

Reaction equation

HRID 1955108 reaction equation
[NH:1]1[CH:5]=[CH:4][N:3]=[CH:2]1.P([O-])([O-])([O-])=O.[K+].[K+].[K+].[F:14][C:15]1[CH:16]=[C:17]([N+:22]([O-:24])=[O:23])[CH:18]=[CH:19][C:20]=1F>CS(C)=O.C(OCC)(=O)C>[F:14][C:15]1[CH:16]=[C:17]([N+:22]([O-:24])=[O:23])[CH:18]=[CH:19][C:20]=1[N:1]1[CH:5]=[CH:4][N:3]=[CH:2]1

Participants

6

Reactant 3

HCID 795ImidazoleHCID 62657Potassium Phosphate, TribasicHCID 1230531,2-Difluoro-4-nitrobenzene

Product 1

HCID 53061531-(2-fluoro-4-nitrophenyl)-1H-imidazoleYield 92.2%

Reagents, catalysts & solvents 2

HCID 679Dimethyl SulfoxideSolventHCID 8857Ethyl AcetateSolvent

Conditions

Temperature
90 °C

Procedure

A solution of 2.14 g(31.4 mmol) of imidazole and 10.9 g(62.8 mmol) of dibasic potassium phosphate in 190 mL DMSO was treated with 5.25 g(3.7 mL, 50.9 mmol) of 3,4-difluoronitrobenzene followed by warming at 90° C. for 18 h. The solution was diluted with ethyl acetate and was extracted with water. The water layer was back-extracted with ethyl acetate and the combined organic layers were then extracted with water (2×). The organic layer was dried (Na2SO4) and concentrated in vacuo to afford a brown solid. This material was chromatographed over 250 g of 230-400 mesh silica gel, eluting with dichloromethane, and then with 1%(v/v) methanol in dichloromethane, and finally with 2%(v/v) methanol in dichloromethane. These procedures afforded 6.0 g(92%) of the title compound as a bronze colored solid. 1H NMR (CDCl3): δ8.17, 7.96, 7.63, 7.35, 7.26.

Workup

  1. extractionwas extracted with water
  2. extractionThe water layer was back-extracted with ethyl acetate
  3. extractionthe combined organic layers were then extracted with water (2×)
  4. dry with materialThe organic layer was dried (Na2SO4)
  5. concentrationconcentrated in vacuo
  6. customto afford a brown solid
  7. customThis material was chromatographed over 250 g of 230-400 mesh silica gel
  8. washeluting with dichloromethane

Sources & evidence

ORD record
ord-d01bbdbcef2e469e863b24f53b3731ed
Source dataset
uspto-grants-2000_09
Patent number
US06124334

Reaction notes

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